In a simulated head-on crash test, a car impacts a wall at 25 mi/h (40 km/h) and comes abruptly to rest. A 120 lb passenger dummy (with a mass of 55 kg), without a seat belt, is stopped by an air bag, which exerts a force on the dummy of 3000 lb. How long was the dummy in contact with the air bag while coming to a stop?
Physics - drwls, Thursday, November 25, 2010 at 2:40pm
The 3000 lb force exerted by the air bag is 13,360 Newtons.
Force x time = Momentum change = M V
The initiaL dummy momentum is 55 kg*11.12 m/s = 612 kg m/s
time = 612 kg m/s/13,360 kg m/s^2 = 0.046 s