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

Explanation

It is given that weight of person on the earth = w (i.e., w = mg)
And as he can jump upto height `(h_(1)=0.4m)`
So, potential energy at this point `=mgh=mgxx.04" ".....(i)`
And it is given that
weight of the person on the other planet `=(W)/(2)`
And if he could jump to height `(h_(2))` its potential energy would be `(W)/(2)h_(2)=(mg)/(2)h_(2)" ".....(ii)`
Since, he applied same amounts of effort in both the cases to lift his body, so its potential energy will be same.
And from Eqs. (i) and (ii)
`0.4=(mg)/(2)h_(2)`
`rArrh_(2)0.4xx2=0.8m`