Question

Q- A ball of mass 2 kg is dropped from a height . what is the work done by its weight in 2 seconds after the ball is dropped?

Answer 1

The question is ambiguous. where is tje height part of the que.

Answer 2

distance it falls: 

h = ½gt² = ½(9.8)(2)² = 19.6 meters 

speed after 2 sec 

v = gt = 19.6 m/s 

PE lost = mgh = 2•9.8•19.6 = 384 J 

KE gained = ½mV² = ½(2)(19.6)² = 384 J 

now workdone =change in kinetic energy

at t=0 k.e=0

at t=2 k.e=384 joules

answer is 384 joules