Question

While testing the safety of a car, a dummy driver is used and the car is propelled at different speeds to hit a rigid wall. In one such test, the dummy driver had a mass of 70 kg and the speed of the car just before the impact was 40m/s. If the time interval between the collision and the car coming to rest was 0.2 s,then find the deceleration of the car due to impact

Answer 1

Answer:

200m/s^2

Explanation:

as the dummy moves together with the car, lets take the deceleration of car is same as that of the rate bt which the dummy decelerate

so deceleration =dv/dt=(v1-v2)/dt

v1=40m/s

v2=0

dt=0.2 sec=2*10^-1 sec

deceleration=40-0/(2/10)=200 m/s^2