Gurumuda Networks
Free fall motion – problems and solutions
1. A stone free fall from the height of 45 meters. If the acceleration due to gravity is 10 ms-2, what is the speed of the stone when hits the ground?
Known :
Height (h) = 45 meters
Acceleration due to gravity (g) = 10 m/s2
Wanted : The final velocity of the stone when it hits the ground (vt)
Heat transfer conduction – problems and solutions
1. Two metals have the same size but different type. The thermal conductivity of P = 2 times the thermal conductivity of Q. What is the temperature between the two metals, as shown in the figure below.
Known :
kQ = k
kP = 2k
Wanted: Temperature between the two metals
Rotational motion – problems and solutions
Torque
1. A beam 140 cm in length. There are three forces acts on the beam, F1 = 20 N, F2 = 10 N, and F3 = 40 N with direction and position as shown in the figure below. What is the torque causes the beam rotates about the center of mass of the beam?
Known :
The center of mass located at the center of the beam.
Electric field – problems and solutions
1. Point A located at the center between two charges. Both charges have the same magnitude but opposite sign and separated by a distance of a. The magnitude of the electric field at point A is 36 N/C. If point A moved 1/2a close to one of both charges, what is the magnitude of the electric field at point A?
Known :
Charge 1 (q1) = +Q
Charge 2 (q2) = -Q
The distance between charge 1 and point A (r1A) = ½ a
Electric force – problems and solutions
1. Three charges as shown in the figure below. What is the electric force experienced by charge B. k = 9 x 109 Nm2C−2, 1 μC = 10−6 C.
Known :
qA = 10 µC = 10 x 10-6 C = 10-5 Coulomb
qB = 10 µC = 10 x 10-6 = 10-5 Coulomb
qC = 20 µC = 20 x 10-6 = 2 x 10-5 Coulomb
Static electricity – problems and solutions
Electric force
1. Point A in an electric field. The magnitude of the electric field at point A = 0.5 NC-1. If a 0.25-C charge placed at point A, then what is the electric force exerted on the charge.
Known :
Electric field at point A = 0.5 NC-1
Electric charge at point A = 0.25 C
Wanted: Electric force
Newton’s laws of motion – problems and solutions Newton’s first law of motion 1. If no net force acts on an object, then : (1) the object is not accelerated (2) object at rest (3) the change of velocity of an object = 0 (4) the object can not travels at a constant velocity Which … Read more
Linear motion – problems and solutions 1. Graph of velocity (v) vs. time (t) shown in the figure below. What is the deceleration according to the graph. Solution A-B = motion at constant acceleration, B-C = motion at constant velocity, C-D = motion at constant deceleration. 2. Graph of linear motion shown in the figure … Read more
Hooke’s law and elasticity – problems and solutions The change in length 1. A rod has a length of L, pulled by a force of F. The amount of elongation is ∆L. What is the magnitude of the force if the change in length is 4∆L. Known : Force 1 (F1) = F The change … Read more
Centripetal force – problems and solutions 1. A 200-gram ball, attached to the end of a cord, is revolved in a horizontal circle with an angular speed of 5 rad s-1. If cord’s length is 60 cm, what is the centripetal force? Known : Object’s mass (m) = 200 gr = 200/1000 kg = 2/10 … Read more