A body of 200 grams falls from a 25 meter altimeter calculate the potential energy

The body didn't need to fall in order to have potential energy.

It had potential energy just by being 25 meters off the ground ... that's the work that somebody had to do to lift the body 25 meters off the ground.

It loses all that potential energy as it falls, so let's calculate the potential energy it had before it fell:

Potential energy = (mass) (gravity) (height).

200 grams = 0.2 kg

Gravity on Earth = 9.8 m/s²

Potential energy = (0.2 kg) (9.8 m/s²) (25 m)

Potential energy = 49 Joules