A set of crash tests consists of running a test car moving at a speed of 12.4 m/s (27.7 mi/hr) into a solid wall. Strapped securely in an advanced seat belt system, a 57.0 kilogram (126lbs) dummy is found to move a distance of 0.720 meter from the moment the car touches the wall to the time the car is stopped. Find the size of the average force which acts on the dummy during that time.
Using the direction of motion as the positive direction, find the average acceleration of the dummy during that time (in g's, with 1g =9.81m/s2).
In a different car, the distance the dummy moves while being stopped is reduced from 0.720 m to 0.270 m, Find the average force on the dummy as that cars tops.