physics

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

f= 8/2=4N   

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   

  = 100N

simples no?