Certain force acting on a 20 kg mass changes its velocity from 5 m s−1 to 2 m s−1. Calculate the work done by the force.
Kinetic energy is given by the expression,(Ek)v= 1/2 mv2
Where,
Ek= Kinetic energy of the object moving with a velocity, v
(i) Kinetic energy when the object was moving with a velocity 5 m s-1
(Ek)5= 1/2 x 20 x (5)2 = 250 J
Kinetic energy when the object was moving with a velocity 2 m s-1
(Ek)2= 1/2 x 20 x (2)2 = 40 J.
