Question

A car traveling at 69 km/h hits a bridge abutment. A passenger in the car moves forward a distance of 59 cm (with respect to the road) while being brought to rest by an inflated air bag. What magnitude of force (assumed constant) acts on the passenger's upper torso, which has a mass of 41 kg?

Answer 1

Initial kinetic energy
= (1/2)mv²
Final kinetic energy
= 0
Work done to dissipate this kinetic energy
= F.d
where d = 0.59 m
0.59F = (1/2)41 kg *(69/3.6)²
Solve for F.
(hint: > 10000 N.)

Answer 2

12764.2N