Gravitational potential energy

[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?

[stunner5000pt]

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?

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

[shawonna23]

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

[stunner5000pt]

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

dU = the change in gravitational potential energy

dH = the change in height

Because

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

[Pyrrhus]

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

[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