force = change in momentum f= ▲mom
time taken for change t
ie. force = rate of change in momentum
calculate the force needed to change the momentum of an object by 8kgm/s in 2 sec
a car (mass 1000kg) travelling at 10 m/s stops after 100s what force did the brakes exert?
f= ▲mom mom=mv
t =1000 x 10
= 10000 =10000 kgm/s