Question

A 4 kg block is pushed up an incline that makes a 30° angle with the horizontal, as shown in the figure. Once the block is pushed a distance of d = 5.0 m up the incline, the block remains at rest.
What is the approximate change in the gravitational potential energy of the block-Earth system when the block is held at rest compared to its original location at the bottom of the incline?
A) OJ
B) 100 J
C) 100/33 J
D) 200 J

Answer 1

Answer:

  B)  100 J

Explanation:

Assuming the distance given is measured along the incline, the vertical change in height is (5 m)(sin 30°) = 2.5 m. Then the change in potential energy is ...

  ∆PE = mg(∆h) = (4 kg)(10 m/s^2)(2.5 m) = 100 J