Sarah, who has a mass of 55 kg, is riding in a car at 20 m/s. she sees a cat crossing the street and slams on the brakes! her seatbelt stops her from flying forward, bringing her to rest in 0.5 seconds. how much force did the seatbelt put on sarah?

-2200 Kg/m^2 force is exerted in opposite direction by seat belt.

Explanation:

Change in momentum = force multiplied by time.

m(Vf - Vi ) =F * t

m(Vf - Vi ) = 55(0-20)= -1100

F = -1100/0.5= -2200

-2200 Kg/m^2 force is exerted in opposite direction by seat belt.