Question
If we throw a body upwards with velocity of 4 m/s, at what height does its kinetic energy reduce to half of the initial value? ( Take g = 10 ms-1 )
4 m
2 m
1m
0.4 m
Solution
D.
0.4 m
At a given height the half of the kinetic energy of the body is equal to the potential energy.
Initial kinetic energy of the body
= 8 m
Let at height h, the kinetic energy reduces to half, i.e, it becomes 4 m. It is also equal to potential energy. Hence
mgh = 4 m
h = 0.4 m
