Question

Calculate the potential energy of a 5 kg object sitting on a
3 meter ledge.

Answer 1

Use gravitational potential energy U = m g h.

With m = 5 kg, h = 3 m, and g ≈ 9.8 m/s²:

U = 5 × 9.8 × 3 = 147 J

So the object has about 147 joules of potential energy relative to the chosen reference (e.g., ground).