A 60kg front seat passenger in a car moving initially with a speed of 18m/s (40 MPH) is brought to rest by an air bag in a time of 0.4s

Question

a. What is the impulse acting on the passenger?
b.What is the average force acting on the passenger in this process?

Answer 1

40 Miles/hr is actually 17.88 m/s, not 18, but let's say it's 18.
The initial momentum, is 60*18 = 1080 kg m/s.
That equals the impulse and the momentum change hen stopping.

Divide the impulse by the time (in seconds) for the average force, in newtons.

Fav = 1080/0.4 = ___ N

Answer 2

2700