High School

A skier with a potential energy of [tex]$137,200 \, \text{J}$[/tex] waits on top of a ski jump that is 200 m high. What is the mass of the skier?

A. 20 kg
B. 70 kg
C. 137 kg
D. 686 kg

Answer :

To find the mass of the skier, we use the formula for potential energy:

[tex]\[ \text{Potential Energy} = \text{mass} \times \text{gravity} \times \text{height} \][/tex]

In this equation:
- Potential Energy (PE) is given as 137,200 Joules.
- Gravity (g) is approximately 9.8 m/s² (constant acceleration due to gravity).
- Height (h) is given as 200 meters.

We need to solve for the mass (m). To do this, rearrange the formula:

[tex]\[ \text{mass} = \frac{\text{Potential Energy}}{\text{gravity} \times \text{height}} \][/tex]

Substituting the given values:

[tex]\[ \text{mass} = \frac{137,200}{9.8 \times 200} \][/tex]

Calculate the denominator:

[tex]\[ 9.8 \times 200 = 1,960 \][/tex]

Then divide the potential energy by this result:

[tex]\[ \text{mass} = \frac{137,200}{1,960} \approx 70 \][/tex]

Therefore, the mass of the skier is approximately 70 kg. The closest option to this result is 70 kg.