The weight of a person on a planet A is about half that on the earth. He can jump upto 0.4 m height on the surface of the earth. How high he can jump on the planet A?

The PE will remain same on the earth and on planet A.

Mass is same on both the surface since we are talking about the same person, now weight = mg such that

Weight on earth = 2(weight on planet A)

Mg on earth = 2(Mg’ on planet A)

Equating PE on both the planets.

∴ Mgh on earth = Mg’h’ on planet A

2Mg’h = Mg’h’

2h =h’

h’ = 2(0.4) = 0.8 m