{"id":145,"date":"2018-01-16T11:59:09","date_gmt":"2018-01-16T03:59:09","guid":{"rendered":"https:\/\/gurumuda.net\/physics\/?p=145"},"modified":"2018-01-16T11:59:09","modified_gmt":"2018-01-16T03:59:09","slug":"mass-and-weight-problems-and-solutions","status":"publish","type":"post","link":"https:\/\/gurumuda.net\/physics\/mass-and-weight-problems-and-solutions.htm","title":{"rendered":"Mass and weight \u2013 problems and solutions","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"

Solved problems in Newton’s laws of motion – Mass, and weight<\/a><\/p>\n

1. The weight of a 1 kg mass at the surface of the Earth is… g = 9.8 m\/s<\/span><\/span>2<\/span><\/span><\/sup><\/p>\n

Known :<\/u><\/span><\/span><\/p>\n

Mass (m) = 1 kg<\/span><\/span><\/p>\n

The acceleration due to gravity at the surface of the Earth<\/a> (g) = 9.8 m\/s<\/span><\/span>2<\/span><\/span><\/sup><\/p>\n

Wanted: weight (w) <\/span><\/span><\/p>\n

Solution :<\/u><\/span><\/span><\/p>\n

w = m g <\/span><\/span><\/p>\n

m = mass (The SI unit of mass is the kilogram, kg)<\/span><\/span><\/p>\n

g = acceleration due to gravity (The SI unit of g is m\/s<\/span><\/span>2<\/span><\/span><\/sup>)<\/span><\/span><\/p>\n

w = weight (The SI unit of w is kg m\/s<\/span><\/span>2<\/span><\/span><\/sup> or Newton)<\/span><\/span><\/p>\n

Weight :<\/b><\/span><\/span><\/p>\n

w = (1 kg)(9.8 m\/s<\/span><\/span>2<\/span><\/span><\/sup>) = 9.8 kg m\/s<\/span><\/span>2<\/span><\/span><\/sup> = 9.8 Newton<\/span><\/span><\/p>\n

<\/p>\n

2. <\/span><\/span><\/p>\n

(a) Draw the force of gravity (weight)<\/a> that act on the object when the object is at rest on a table, as shown in figure (a). <\/span><\/span><\/p>\n

(b) Draw the force of gravity (weight) and it’s components that act on an object sliding down an inclined plane<\/a>, as shown in figure (b)<\/span><\/span><\/p>\n

\"Mass<\/p>\n

Solution<\/u><\/span><\/span><\/p>\n

\"Mass<\/p>\n

The direction of the weight is downward toward the center of the Earth.<\/span><\/span><\/p>\n

w<\/span><\/span>x<\/span><\/sub> = the horizontal component of the weight and w<\/span><\/span>y<\/span><\/sub> = the vertical component of the weight<\/span><\/span><\/p>\n

<\/p>\n

3. The mass of a box is 1 kg and acceleration due to gravity is 9.8 m\/s<\/span><\/span>2<\/span><\/span><\/sup>. Find (a) weight (b) the horizontal component and the vertical component of the weight.<\/span><\/span><\/p>\n

\"MassSolution<\/u><\/span><\/span><\/p>\n

Weight : w = m g = (1 kg)(9.8 m\/s<\/span><\/span>2<\/span><\/span><\/sup>) = 9.8 kg m\/s<\/span><\/span>2<\/span><\/span><\/sup> = 9.8 Newton<\/span><\/span><\/p>\n

The horizontal component of the weight :<\/span><\/span><\/p>\n

w<\/span><\/span>x<\/span><\/sub> = w sin 30<\/span><\/span>o<\/span><\/span><\/sup> = (9,8 N)(0,5) = 4.9 Newton<\/span><\/span><\/p>\n

The vertical component of the weight :<\/span><\/span><\/p>\n

w<\/span><\/span>y<\/span><\/sub> = w cos 30<\/span><\/span>o<\/span><\/span><\/sup> = (9.8 N)(0.5\u221a3) = 4.9\u221a3 Newton<\/span><\/span><\/p>\n

<\/p>\n

[wpdm_package id=’458′]<\/p>\n

    \n
  1. Mass and weight<\/a><\/li>\n
  2. Normal force<\/a><\/li>\n
  3. Newton’s second law of motion<\/a><\/li>\n
  4. Friction force<\/a><\/li>\n
  5. Motion on the horizontal surface without friction force<\/a><\/li>\n
  6. The motion of two bodies with the same acceleration on the rough horizontal surface with the friction force<\/a><\/li>\n
  7. Motion on the inclined plane without friction force<\/a><\/li>\n
  8. Motion on the rough inclined plane with the friction force<\/a><\/li>\n
  9. Motion in an elevator<\/a><\/li>\n
  10. The motion of bodies connected by cord and pulley<\/a><\/li>\n
  11. Two bodies with the same magnitude of accelerations<\/a><\/li>\n
  12. Rounding a flat curve – dynamics of circular motion<\/a><\/li>\n
  13. Rounding a banked curve – dynamics of circular motion<\/a><\/li>\n
  14. Uniform motion in a horizontal circle<\/a><\/li>\n
  15. Centripetal force in uniform circular motion<\/a><\/li>\n<\/ol>\n

    <\/p>\n","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"excerpt":{"rendered":"

    Solved problems in Newton’s laws of motion – Mass, and weight 1. The weight of a 1 kg mass at the surface of the Earth is… g = 9.8 m\/s2 Known : Mass (m) = 1 kg The acceleration due to gravity at the surface of the Earth (g) = 9.8 m\/s2 Wanted: weight (w) … 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":"Mass and weight \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-145","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\/145","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=145"}],"version-history":[{"count":0,"href":"https:\/\/gurumuda.net\/physics\/wp-json\/wp\/v2\/posts\/145\/revisions"}],"wp:attachment":[{"href":"https:\/\/gurumuda.net\/physics\/wp-json\/wp\/v2\/media?parent=145"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/gurumuda.net\/physics\/wp-json\/wp\/v2\/categories?post=145"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/gurumuda.net\/physics\/wp-json\/wp\/v2\/tags?post=145"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}