Question

When a force applied to a body of mass 1 kg it's velocity changes from 10m/s to 20m/s in 2 sex. The rate of change of momentum of the body is: A) 5N B) 20N C) 10N D) zero

Answer 1

m=1 kg
v=20 m/s
u=10 m/s
v-u=20-10=10 m/s
t=2 sec
rate of change of momentum=m(v-u)/t
                                              =1(10)/2
                                              =5N

Answer 2

rate of change in momentum= mv-mu/t
=1×20-1×10/2
=10/2
=5kgm/s