Question

a 60kg woman is a passenger in a car that is involved in a crash. she is wearing a seat belt that stops her in 0.1s. if the car gad been travelling at 12m/s before the crash calculate the deceleration and the force on her breastbone due to the seat belt?


can you assume that v=om/s and u= 12m/s? so using v=u+at work out accel and then f=m.a for the force?

Answer 1

a = (0-12)/.1

F * t = change in m v
F * 0.1 = 60 (0-12)

Answer 2

a = change in velocity / change in time
and
F = change in momentum / change in time (Newton #2, F = d/dt (m v) = m a if m is constant)