You want to climb to the top of a wall that is 2.0 m high, using a ramp. You have a choice of several arrangements for the ramp regarding the length and the angle. Which of the following arrangements would you choose to climb to the top so that you do the least work?
A)2.8 m at 45°
B)4.0 m at 30°
C)11.5 m at 10°
D)The length makes no difference.

Question

Quizplus · Accepted Answer

The work done against gravity to reach the top of the wall is the same for all ramp arrangements, as it depends only on the vertical height (2.0 m) and not on the length of the ramp or the angle. The work done is equal to the gravitational potential energy gained, which is mgh, where m is the mass, g is the acceleration due to gravity, and h is the height.

You Want to Climb to the Top of a Wall