Question

If a hiker that weighs 600 newtons climbs a 50 meter hill, how much gravitational potential energy has the hiker gained?

Answer 1

The gravitational potential energy U is defined as the product of mass m, the acceleration of gravity g and the height of object h.

$U = mgh$

We do not have the mass of the hiker. But we know that its W weight is:

$W = mg$

Where

$g = 9.8 m/s^2$

So:

$m = \frac{W}{g}\\\\m = \frac{600}{g}$.

So:

$U = (\frac{600}{g})gh\\\\U = (600N)(50m)$

$U = 30000$J

The hiker has gained 30,000 J of energy