Question

A sphere of mass 4kg is dropped from a certain height. After 5s, its kinetic energy is

Answer 1

kindly refer attached image for solution you requested

Answer 2

v = u +at
u = 0 ( dropped means initial at rest)
a= 10m/s^-2
and t=5 sec (given)
v=10×5 = 50
k.E. = 1/2mv^2
= 1/2 × 4 (50)^2
=5000 j or 5kj