Solve the all parts of given problem:

Problem: During a front-end car collision from 47.5 km/h and with air bags inflated, the acceleration limit for the chest is 60g as the car comes to rest. The trunk or chest area of the body comprises about 43% of body weight. Draw a free-body diagram of a person during the crash centered on the origin of the axes. The diagram does not need to be drawn to precise scale. Assume the car is traveling from left to right along the x-axis.

Part A: For how much time does this acceleration last, assuming it is constant at 60g?

Part B: What force in Newton's does the air bag exert on the chest of a 78.5 kg person?

I don't know how to get that answer for above problem. Please help.