A particle of mass m is released from a certain height h with zero initial velocity. It strikes the ground elastlcally (direction of its velocity is reversed but magnitude remains the same). Plot the graph between its kinetic energy and time till it returns to its initial position.

Answer

A, C, D

Explanation

Kinetic energy will first increase and then decrease.
`v=gt` (in downwards journey)
`:. K.E.=1/2 mv^2=1/2mg^2t^2`
Hence, KE versus t graph is a parabola.