Question

A body of mass 2 kg moving on a horizontal surface
with an initial velocity of 4 m/s comes to rest after
2 s. If one wants to keep this body moving on the
same surface with a velocity of 4 m/s, the force
required is :-​

Answer 1

u=4m/s ,v=0, t=2sec ,a=v-u/t=0-4/2=-2m/s^2 f=ma=2×-2=-4N