Question

A force of 2n acting on a body changes its velocity uniformily from 2 m/s to 5m/s in 10s.Calculate the momentum of the body

Answer 1

Here, force =2N,time =10s.
Therefore, force =mass*acceleration
Or, F=ma
F=m*delta v/t
F*t=mv
Or, mv=2*10
Therefore,momentum=20kgm/s

Answer 2

we know that
Force=dp/dt= mdv/dt = m∆v/t=2
p = momentum

or m(5-2)/10=2

or (mass)m=2*10/3

or m= 6.667 kg

hence intial momentum= 6.667*2 kgm/s

final momentum= 6.667*5 kgm/s

hope this will help you.....