Question

A car of mass 1200kg is brought to rest from speed of 20m/s by constant force of 3000N calculate change in momentum produced by force and time taken by car to come to rest

Answer 1

Answer:

given F=3000N

also F=ma

so a=3000/1200

=2.5m/s^2

now applying 1nd law of motion

v=u+at

here v=0

u=20m/s

so eqn will be

0=20-2.5t

so t=20/2.5

=8s

since momentum =mv and final momentum is 0 because final v is 0.

so change in momentum =-mu

=-1200×20 Nm/s

=-24000 Nm/s