{"id":1259,"date":"2018-02-28T15:34:57","date_gmt":"2018-02-28T07:34:57","guid":{"rendered":"https:\/\/gurumuda.net\/physics\/?p=1259"},"modified":"2018-02-28T15:34:57","modified_gmt":"2018-02-28T07:34:57","slug":"the-magnitude-of-net-torque-problems-and-solutions","status":"publish","type":"post","link":"https:\/\/gurumuda.net\/physics\/the-magnitude-of-net-torque-problems-and-solutions.htm","title":{"rendered":"The magnitude of net torque \u2013 problems and solutions","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">1. A force P is applied to one end of a beam with a length of 2 m. What is the magnitude of the <a href=\"https:\/\/gurumuda.net\/physics\/the-magnitude-of-net-torque-problems-and-solutions.htm\" target=\"_blank\" rel=\"noopener\">torque<\/a>? The axis of rotation at point A. <\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><u><img loading=\"lazy\" decoding=\"async\" class=\"alignleft size-full wp-image-1260\" src=\"https:\/\/gurumuda.net\/physics\/wp-content\/uploads\/2018\/02\/The-magnitude-of-net-torque-\u2013-problems-and-solutions-1.png\" alt=\"The magnitude of net torque \u2013 problems and solutions 1\" width=\"157\" height=\"87\" \/>Known :<\/u><\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">Force (F) = 10 N<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">Length of AB (r<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">AB<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">) = 2 m<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i>Force F is perpendicular to the beam. <\/i><\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">The lever arm (l<\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">) <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">= r<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">AB <\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">sin 90<\/span><\/span><sup><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">o <\/span><\/span><\/sup><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">= (2 m)(1) = 2 m <\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><u>Wanted:<\/u><\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> The torque about the axis of rotation<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><u>Solution :<\/u><\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">The torque :<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">\u03c4<\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> = F l = (10 N)(2 m) = 20 N m<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i>The plus sign because the beam <\/i><\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><span lang=\"en-US\"><i>rotates counterclockwise rotation.<\/i><\/span><\/span><\/span><i> <\/i><\/p>\n\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">2. The length of a beam <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">AB is 2 m and the magnitude of force F is 10 N. What is the magnitude of the torque? The axis of rotation at point A. <\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><u><img loading=\"lazy\" decoding=\"async\" class=\"alignleft size-full wp-image-1261\" src=\"https:\/\/gurumuda.net\/physics\/wp-content\/uploads\/2018\/02\/The-magnitude-of-net-torque-\u2013-problems-and-solutions-2.png\" alt=\"The magnitude of net torque \u2013 problems and solutions 2\" width=\"156\" height=\"88\" \/>Known :<\/u><\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">Force (F) = 10 N<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">Length of AB (r<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">AB<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">) = 2 m<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">The lever arm (l<\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">) <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">= r<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">AB <\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">sin 60<\/span><\/span><sup><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">o <\/span><\/span><\/sup><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">= (2 m)(0.5<\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">\u221a3<\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">) = <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">\u221a3 <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">m<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><u>Wanted:<\/u><\/span><\/span> <span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">The torque about the axis of rotation<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><u>Solution :<\/u><\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">The torque :<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">\u03c4<\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> = F l = (10 N)(<\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">\u221a3 <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">m) = 10<\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">\u221a3 <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">N m<\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i>The plus sign because the force F causes the beam <\/i><\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><span lang=\"en-US\"><i>rotates counterclockwise rotation.<\/i><\/span><\/span><\/span><i> <\/i><\/p>\n<p align=\"justify\"><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">3. The length of a beam is 2 m. The magnitude of F<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">1<\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> is 10 N and the magnitude of F<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">2<\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> is 15 N. Determine the net torque about the center of the beam. <\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i>The axis of rotation at the center of the beam.<\/i><\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><u><img loading=\"lazy\" decoding=\"async\" class=\"alignleft size-full wp-image-1262\" src=\"https:\/\/gurumuda.net\/physics\/wp-content\/uploads\/2018\/02\/The-magnitude-of-net-torque-\u2013-problems-and-solutions-3.png\" alt=\"The magnitude of net torque \u2013 problems and solutions 3\" width=\"168\" height=\"119\" \/>Known :<\/u><\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">Force 1 (F<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">1<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">) = 10 N<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">The <a href=\"https:\/\/gurumuda.net\/physics\/distance-and-displacement-problems-and-solutions.htm\" target=\"_blank\" rel=\"noopener\">distance<\/a> between F<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">1<\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> and the center of beam (r<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">1<\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">) = 1 m <\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">The lever arm 1 (l<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">1<\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">) <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">= r<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">1 <\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">sin 90<\/span><\/span><sup><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">o <\/span><\/span><\/sup><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">= (1 m)(1) = 1 m<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i>Force F<\/i><\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><i>1<\/i><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i> is perpendicular to the beam. <\/i><\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">Force 2 (F<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">2<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">) = 15 N<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">The distance between F<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">2<\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> and the center of the beam (r<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">2<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">) = 1 m<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i>Force F<\/i><\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><i>2<\/i><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i> is perpendicular to the beam. <\/i><\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">The lever arm 2 (l<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">2<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">) <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">= r<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">1 <\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">sin 90<\/span><\/span><sup><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">o <\/span><\/span><\/sup><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">= (1 m)(1) = 1 m<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><u>Wanted :<\/u><\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> T<\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">he net torque about the axis of rotation<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><u>Solution :<\/u><\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">The torque 1 : <\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">\u03c4<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">1<\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> = F<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">1<\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> l<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">1<\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> = (10 N)(<\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">1 <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">m) = 10<\/span><\/span> <span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">N m<\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i>The plus sign because the force of F<\/i><\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i>1 <\/i><\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i>causes the beam <\/i><\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><span lang=\"en-US\"><i>rotates counterclockwise rotation.<\/i><\/span><\/span><\/span><i> <\/i><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">The torque 2 : <\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">\u03c4<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">2<\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> = F<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">2<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> l<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">2 <\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">= (15 N)(<\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">1 <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">m) = -15 N <\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i>The minus sign because the force F<\/i><\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i>2<\/i><\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i> causes the beam to <\/i><\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><span lang=\"en-US\"><i>rotates clockwise.<\/i><\/span><\/span><\/span><i> <\/i><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">The net torque :<\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Ubuntu,serif\"><span style=\"font-size: medium\">\u03a3<\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">\u03c4 = \u03c4<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">1 <\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">\u2013 \u03c4<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">2 <\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">= 10 \u2013 15 = &#8211; 5 N m <\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i>The minus sign because the beam to <\/i><\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><span lang=\"en-US\"><i>rotates clockwise.<\/i><\/span><\/span><\/span><i> <\/i><\/p>\n<p align=\"justify\"><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">4. The length beam AB is <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">2 m, The magnitude of F<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">1<\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> is 10 N and the magnitude of F<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">2 <\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">is <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">10 N. Determine the net torque about the center of the beam. <\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i><img loading=\"lazy\" decoding=\"async\" class=\"alignleft size-full wp-image-1263\" src=\"https:\/\/gurumuda.net\/physics\/wp-content\/uploads\/2018\/02\/The-magnitude-of-net-torque-\u2013-problems-and-solutions-4.png\" alt=\"The magnitude of net torque \u2013 problems and solutions 4\" width=\"158\" height=\"95\" \/>The axis of rotation at the center of the beam.<\/i><\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><u>Known :<\/u><\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">Force 1 (F<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">1<\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">) = 10 Nn<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">The distance between F<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">1<\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> and the center of the beam (r<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">1<\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">) = 1 m<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">The lever arm 1 (l<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">1<\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">) <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">= r<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">1 <\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">sin 60<\/span><\/span><sup><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">o <\/span><\/span><\/sup><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">= (1 m)(0.5<\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">\u221a3<\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">) = 0.5<\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">\u221a3 <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">m<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">Force 2 (F<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">2<\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">) = 10 N<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">The distance between F<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">2<\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> and the center of the beam (r<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">2<\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">) = 1 m<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i>Force F<\/i><\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i>2<\/i><\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i> is perpendicular to the beam. <\/i><\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">The lever arm 2 (l<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">2<\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">) = r<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">2 <\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">sin 90<\/span><\/span><sup><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">o <\/span><\/span><\/sup><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">= (1 m)(1) = 1 m<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><u>Wanted :<\/u><\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> The net torque about the axis of rotation<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><u>Solution :<\/u><\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">The torque 1 :<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">\u03c4<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">1<\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> = F<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">1<\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> l<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">1<\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> = (10 N)(<\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">0.5<\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">\u221a3 <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">m) = <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">5<\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">\u221a3 = 8.7 N.m<\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i>The plus sign because the force F<\/i><\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i>1<\/i><\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i> causes the beam to <\/i><\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><span lang=\"en-US\"><i>rotates clockwise.<\/i><\/span><\/span><\/span><i> <\/i><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">The torque 2 :<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">\u03c4<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">2<\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> = F<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">2<\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> l<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">2 <\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">= (10 N)(<\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">1 <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">m) = -10 N m<\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i>The minus sign because the force F<\/i><\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i>2<\/i><\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i> causes the beam to <\/i><\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><span lang=\"en-US\"><i>rotates clockwise.<\/i><\/span><\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">The net torque :<\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Ubuntu,serif\"><span style=\"font-size: medium\">\u03a3<\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">\u03c4 = \u03c4<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">1 <\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">\u2013 \u03c4<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">2 <\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">= 8.7 \u2013 10 = &#8211; 1.3 N m<\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i>The minus sign because the net force causes the beam to <\/i><\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><span lang=\"en-US\"><i>rotates clockwise.<\/i><\/span><\/span><\/span><i> <\/i><\/p>\n<p align=\"justify\"><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">5. The length of a beam is 10 m, the magnitude of F<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">1 <\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">is 10 N, the magnitude of F<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">2<\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> is 10 N and the magnitude of F<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">3<\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> is 15 N. The distance between point A and point C is 7.5 m. The Force F<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">2<\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> located at the center of the beam. Determine the net torque about the point C located at 2.5 m from the point B. <\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i>The axis of rotation located at point C<\/i><\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><u><img loading=\"lazy\" decoding=\"async\" class=\"alignleft size-full wp-image-1264\" src=\"https:\/\/gurumuda.net\/physics\/wp-content\/uploads\/2018\/02\/The-magnitude-of-net-torque-\u2013-problems-and-solutions-5.png\" alt=\"The magnitude of net torque \u2013 problems and solutions 5\" width=\"173\" height=\"167\" \/>Known :<\/u><\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">Force 1 (F<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">1<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">) = 10 N<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">The distance between F<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">1<\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> and point C (r<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">1<\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">) = <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">2.5 <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">m<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i>Force F<\/i><\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><i>1<\/i><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i> is perpendicular to the beam. <\/i><\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">The lever arm 1 (l<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">1<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">) <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">= r<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">1 <\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">sin 90<\/span><\/span><sup><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">o <\/span><\/span><\/sup><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">= (<\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">2.5 <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">m)(<\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">1<\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">) = <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">2.5<\/span><\/span> <span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">m<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">Force 2 (F<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">2<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">) = 10 N<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">The distance between F<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">2<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> and point C (r<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">2<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">) = <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">2.5 <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">m<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i>The force F<\/i><\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><i>2<\/i><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i> is perpendicular to the beam. <\/i><\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">The lever arm 2 (l<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">2<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">) = r<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">2 <\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">sin 90<\/span><\/span><sup><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">o <\/span><\/span><\/sup><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">= (<\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">2.5 <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">m)(1) = <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">2.5 <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">m<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">Force 3 (F<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">3<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">) = 15 N<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">The distance between F<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">3<\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> and point <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">C (r<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">3<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">) = 7.5 m<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i>The force F<\/i><\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><i>3<\/i><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i> is perpendicular to the beam. <\/i><\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">The lever arm 3 (l<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">3<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">) = r<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">3<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> sin 90<\/span><\/span><sup><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">o <\/span><\/span><\/sup><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">= (7.5 m)(1) = 7.5 m<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><u>Wanted :<\/u><\/span><\/span> <span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">The net torque about the axis of rotation<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><u>Solution :<\/u><\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">The torque 1 :<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">\u03c4<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">1<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> = F<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">1<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> l<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">1<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> = (10 N)(<\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">2.5 <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">m) = <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">25 <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">N m<\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i>The plus sign because the force F<\/i><\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i>1<\/i><\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i> causes the beam to <\/i><\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><span lang=\"en-US\"><i>rotates clockwise.<\/i><\/span><\/span><\/span><i> <\/i><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">The torque 2 :<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">\u03c4<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">2<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> = F<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">2<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> l<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">2 <\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">= (10 N)(<\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">2.5<\/span><\/span> <span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">m) = <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">25 N m<\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\">T<span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i>he plus sign because the force F<\/i><\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><i>2<\/i><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i> causes the beam to <\/i><\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><span lang=\"en-US\"><i>rotates clockwise.<\/i><\/span><\/span><\/span><i> <\/i><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">The torque 3 :<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">\u03c4<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">3<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> = F<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">3<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> l<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">3<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> = (15 N)(<\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">7.5 <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">m) = -112..5<\/span><\/span> <span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">N m<\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i>The minus sign because the force F<\/i><\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i>3<\/i><\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i> causes the beam to <\/i><\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><span lang=\"en-US\"><i>rotates clockwise.<\/i><\/span><\/span><\/span><i> <\/i><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">The net torque :<\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Ubuntu,serif\"><span style=\"font-size: medium\">\u03a3<\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">\u03c4 = \u03c4<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">1 <\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">+ \u03c4<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">2 <\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">&#8211; \u03c4<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">3 <\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">= <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">25 <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">+ <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">25 \u2013 112.5 <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">= &#8211; 62.5 N m<\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i>The minus sign because the net force causes the beam to <\/i><\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><span lang=\"en-US\"><i>rotates clockwise.<\/i><\/span><\/span><\/span><i> <\/i><\/p>\n<p align=\"justify\"><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">6. The length of a beam is 10 m, the magnitude of F<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">1<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> is 10 N, the magnitude of F<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">2<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> is 10 N and the magnitude of F<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">3<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> is 10 N. Determine the net torque about point A, located 5 m from the poi<img loading=\"lazy\" decoding=\"async\" class=\"alignleft size-full wp-image-1265\" src=\"https:\/\/gurumuda.net\/physics\/wp-content\/uploads\/2018\/02\/The-magnitude-of-net-torque-\u2013-problems-and-solutions-6.png\" alt=\"The magnitude of net torque \u2013 problems and solutions 6\" width=\"160\" height=\"120\" \/>nt of application of force F<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">1<\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">. <\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i>The axis of rotation at point A.<\/i><\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><u>Known :<\/u><\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">Force 1 (F<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">1<\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">) = 10 N<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">The distance between F<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">1<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> and point A (r<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">1<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">) = 5 m <\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">The lever arm 1 (l<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">1<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">) <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">= r<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">1 <\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">sin 60<\/span><\/span><sup><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">o <\/span><\/span><\/sup><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">= (5 m)(0.5<\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">\u221a3<\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">) = 2.5<\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">\u221a3 <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">m <\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><a href=\"https:\/\/gurumuda.net\/physics\/conservative-force-and-nonconservative-force.htm\" target=\"_blank\" rel=\"noopener\">Force<\/a> 2 (F<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">2<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">) = 10 N<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">The distance between F<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">2<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> and point A (r<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">2<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">) = 0 <\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i>The force F<\/i><\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i>2<\/i><\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i> is perpendicular to the beam.<\/i><\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">The lever arm 2 (l<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">2<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">) = r<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">2 <\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">sin 90<\/span><\/span><sup><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">o <\/span><\/span><\/sup><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">= (0)(1) = 0 <\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">The force 3 (F<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">3<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">) = 10 N<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">The distance between F<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">3<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> and point A (r<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">3<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">) = 10 m <\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">The lever arm 3 (l<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">3<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">) = r<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">3 <\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">sin 30<\/span><\/span><sup><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">o <\/span><\/span><\/sup><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">= (10 m)(0.5) = 5 m <\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><u>Wanted :<\/u><\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> the net torque about the axis of rotation<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><u>Solution :<\/u><\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">The torque 1 :<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">\u03c4<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">1<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> = F<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">1<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> l<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">1<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> = (10 N)(<\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">2.5<\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">\u221a3 m<\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">) = <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">25\u221a3 = 43.3 <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">N m<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i>The plus sign because the force F<\/i><\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><i>1<\/i><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i> causes the beam to <\/i><\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><span lang=\"en-US\"><i>rotates clockwise.<\/i><\/span><\/span><\/span><i> <\/i><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">The torque 2 :<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">\u03c4<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">2<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> = F<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">2<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> l<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">2 <\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">= (10 N)(0) = 0<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">The torque 3 :<\/span><\/span><\/p>\n<p class=\"western\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">\u03c4<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">3<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> = F<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">3<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> l<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">3<\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> = (10 N)(<\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">5 <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">m) = -50<\/span><\/span> <span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">N m<\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i>The minus sign because the force F<\/i><\/span><\/span><sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i>3<\/i><\/span><\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><i> causes the beam to <\/i><\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><span lang=\"en-US\"><i>rotates clockwise.<\/i><\/span><\/span><\/span><i> <\/i><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">The net torque :<\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Ubuntu,serif\"><span style=\"font-size: medium\">\u03a3<\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">\u03c4 = \u03c4<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">1 <\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">+ \u03c4<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">2 <\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">&#8211; \u03c4<\/span><\/span><sub><span style=\"font-family: Times new roman,serif\">3 <\/span><\/sub><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">= <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">43.3 <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">+ 0<\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"> \u2013 50 <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">= &#8211; 6.7 N m<\/span><\/span><\/p>\n<p class=\"western\" align=\"justify\"><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\">The minus sign because the net force causes the beam to <\/span><\/span><span style=\"font-family: Times new roman,serif\"><span style=\"font-size: medium\"><span lang=\"en-US\">rotates clockwise.<\/span><\/span><\/span><!--more--><\/p>\n","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"excerpt":{"rendered":"<p>1. A force P is applied to one end of a beam with a length of 2 m. What is the magnitude of the torque? The axis of rotation at point A. Known : Force (F) = 10 N Length of AB (rAB) = 2 m Force F is perpendicular to the beam. The lever &#8230; <a title=\"The magnitude of net torque \u2013 problems and solutions\" class=\"read-more\" href=\"https:\/\/gurumuda.net\/physics\/the-magnitude-of-net-torque-problems-and-solutions.htm\" aria-label=\"Read more about The magnitude of net torque \u2013 problems and solutions\">Read more<\/a><\/p>\n","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_seopress_titles_title":"","_seopress_titles_desc":"","_seopress_robots_index":"","_seopress_robots_follow":"","_seopress_robots_imageindex":"","_seopress_robots_snippet":"","_seopress_robots_primary_cat":"","_seopress_robots_breadcrumbs":"","_seopress_robots_freeze_modified_date":"","_seopress_robots_custom_modified_date":"","_seopress_robots_canonical":"","_seopress_social_fb_title":"","_seopress_social_fb_desc":"","_seopress_social_fb_img":"","_seopress_social_fb_img_attachment_id":0,"_seopress_social_fb_img_width":0,"_seopress_social_fb_img_height":0,"_seopress_social_twitter_title":"","_seopress_social_twitter_desc":"","_seopress_social_twitter_img":"","_seopress_social_twitter_img_attachment_id":0,"_seopress_social_twitter_img_width":0,"_seopress_social_twitter_img_height":0,"_seopress_redirections_value":"","_seopress_redirections_enabled":"","_seopress_redirections_enabled_regex":"","_seopress_redirections_logged_status":"","_seopress_redirections_param":"","_seopress_redirections_type":0,"_seopress_analysis_target_kw":"The magnitude of net torque \u2013 problems and solutions","_seopress_news_disabled":"","_seopress_video_disabled":"","_seopress_video":[],"_seopress_pro_schemas_manual":[],"_seopress_pro_rich_snippets_disable_all":"","_seopress_pro_rich_snippets_disable":[],"_seopress_pro_schemas":[],"footnotes":""},"categories":[3],"tags":[],"class_list":["post-1259","post","type-post","status-publish","format-standard","hentry","category-solved-problems-in-basic-physics"],"gt_translate_keys":[{"key":"link","format":"url"}],"_links":{"self":[{"href":"https:\/\/gurumuda.net\/physics\/wp-json\/wp\/v2\/posts\/1259","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/gurumuda.net\/physics\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/gurumuda.net\/physics\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/gurumuda.net\/physics\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/gurumuda.net\/physics\/wp-json\/wp\/v2\/comments?post=1259"}],"version-history":[{"count":0,"href":"https:\/\/gurumuda.net\/physics\/wp-json\/wp\/v2\/posts\/1259\/revisions"}],"wp:attachment":[{"href":"https:\/\/gurumuda.net\/physics\/wp-json\/wp\/v2\/media?parent=1259"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/gurumuda.net\/physics\/wp-json\/wp\/v2\/categories?post=1259"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/gurumuda.net\/physics\/wp-json\/wp\/v2\/tags?post=1259"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}