What potential energy relative to the surface of the earth does an apple weighing 150 g

What potential energy relative to the surface of the earth does an apple weighing 150 g, hanging on a branch at a height of 3 m, have?

Potential energy (Ep) is equal to the product of body mass (m), gravitational acceleration (g) and distance from the apple to the ground (h):

Ep = mgh.

Let us express all quantities in SI units:

m = 150 g = 0.15 kg;

g = 10 m / s2;

h = 3 m.

Let’s find the energy:

Ep = 0.15 kg * 10 m / s2 * 3 m = 4.5 J.

Answer: 4.5 J.