Question

A skier with a potential energy of 137,200 J waits on top of a ski jump that is 200 m high. What is the mass of the skier?

Answer 1

The mass of the skier is 70kg.

Answer 2

Remember that the equation for gravitational potential energy is PE = mgy, where PE = potential energy, m=mass, g=acceleration of gravity, and y=distance above your reference level.

You know that PE = 137200J, y = 200m, and g = 9.8
`m/s^(2)`. Plug these values into the equation and solve for m:

`PE = mgy\\ 137200\:J = m(9.8 \: m/s^(2))(200\:m)\\ m = 70 kg`

The mass of the skier is 70kg.