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?

20 kg
70 kg
137 kg
686 kg

Answer 1

70 kg

Step-by-step explanation:

Answer 2

70 kg

Step-by-step explanation:

Potential energy can be found by a product of mass, height and the acceleration of gravity. Here we're given a potential energy of:

`E_p = 137200 J`

A height of:

`h = 200 m`

Acceleration of gravity on Earth:

`g = 9.81 m/s^2`

According to the potential energy equation, we can express it as:

`E_p = mgh`

We may rearrange this equation for mass now:

`m = (E_p)/(gh)`

Substituting the given variables:

`m = (137200 J)/(9.81 m/s^2\cdot 200 m)`

`m = 70 kg`

Therefore, the mass of the skier is 70 kg. Make sure to remember the right units: energy is measured in joules, mass is measured in kilograms, acceleration of gravity is measured in meters per second-squared, height is measured in meters.