Question

The velocity of a body of mass 10 kg increases from 2 metre per second to 8 metre per second when a force acts on it for 3 seconds.
A. What is the momentum after the force acts.
B. What is the momentum before the force acts.
C. What is the value of force.

Answer 1

momentum= mass x velocity

A) momentum after the force acts = m x v

                                                       = 10 x 8=80 kgm/s

B) momentum before the force acts =m x v

                                                            = 10 x 2 = 20 kgm/s

C) force = change in momentum ÷time

            = (final momentum - initial momentum )÷ time

           =( 80-20) ÷3 = 60÷3= 20 N