Homework Help: Gravitational potential energy

1. Oct 12, 2004

shawonna23

A 70.0 kg skier rides a 2860 m long lift to the top of a mountain. The lift makes an angle of 14.8° with the horizontal. What is the change in the skier's gravitational potential energy?

What equation would I use to solve this problem?

2. Oct 12, 2004

stunner5000pt

First of all since the lift is an inclined plane, there is a horizontal and vertical component when 2860 is the hypothenuse

find the vertical component

vertical component is now the dH is dU = MG dH

Last edited: Oct 12, 2004
3. Oct 12, 2004

shawonna23

i don't understand what you are saying. What is dU and dH?

4. Oct 12, 2004

stunner5000pt

dU = the change in gravitational potential energy

dH = the change in height

Because

dU = mgh2 = mgh1 = mg (h2 - h1) = mg dH

5. Oct 12, 2004

Pyrrhus

Remember the trajectory doesn't matter for the gravity potential energy, only the change of height.

6. Oct 13, 2004

kirkmcloren

You know the mass, the unknown is the height.

If the hypotenuse of a triangle is 2860 meters long and the angle is 14.8 degrees what is h?

Then mass x height = potential energy.

:)

Kirk