Question

A 58 kg skier starts at rest from a 24.0 m high hill. They travel to the bottom and then up a second hill to a height of 19.0 m. How much kinetic energy do they have at the top of the second hill?

Answer 1

Answer:

10.791 kJ

Explanation:

Given that,

Mass of the skier, m = 58 kg

Initial position, h₁ = 24 m

Final position, h₂ = 19 m

We need to find the kinetic energy do they have at the top of the second hill.

Using the conservation of energy for both positions.

$v_1=\sqrt{2gh_1} \\\\=\sqrt{2\times 9.8\times 24} \\\\=21.68\ m/s$

And

$v_2=\sqrt{2gh_2} \\\\=\sqrt{2\times 9.8\times 19} \\\\=19.29\ m/s$

Kinetic energy :

$K=\dfrac{1}{2}mv_2^2\\\\K=\dfrac{1}{2}\times 58\times 19.29^2\\\\=10791.01 J\\\\=10.791\ kJ$

So, the kinetic energy they have at the top of the second hill is 10.791 kJ.