Work, Energy, Power, Conservation Laws Problems
Some dynamics SAT Physics exam questions require knowledge of work, potential and kinetic energy, power, conservation laws.
1. An object moves 25m with a constant speed v, as shown in the figure below while a force F = 20N is exerted on the object. What is the work done by the force F?
a) -500J
b) -250J
c) 0J
d) 250J
e) 500J
2. The graph below plots the force exerted on a block of mass m against the displacement of the block. What is the work done by the force F as it moves the box from d = 0 to d = 6?
a) 2J
b) 5J
c) 8J
d) 10J
e) 15J
3. Two forces push simultaneously a stationary 2kg box in opposite directions: F1 acts from left to right and does 150J of work on the box while F2 acts from right to left and does 50J of work on the box. What is the velocity of the box after the work has been done on it?
a) 5m/s
b) 7m/s
c) 10m/s
d) 12m/s
e) 15m/s
4. A soccer ball is kicked vertically from the ground level with a speed of 20m/s. At what height is the gravitational potential energy of the ball maximum?
a) 5m
b) 10m
c) 15m
d) 20m
e) 25m
Solutions