Question

avutons cqual! *71. In a collision, an automobile initially traveling at 60 km/h decelerates at a constant rate of 200 m/s. A passenger not wearing a seat belt crashes against the dashboard. Before the collision, the distance between the passenger and the dash- board was 0.60 m. With what speed, relative to the automo- bile, does the passenger crash into the dashboard? Assume that the passenger has no deceleration before contact with the dashboard.

Answer 1

see Initial velocity of automobile; u= 60 km/h = 60000 m/3600 - 16.67 m/s. So, the passenges also have same initial velocity, u= 16.67 m/s Now, the deccelesation of the automobile, a = 200 m/s2 Distance of the passenges and the dashboard, d = 0-60m,

- 2x 200 x 06 If, o be the final relocity of the automor bile aftes desarelling distance d. then a e2 = u2-2ad. o= v uz-zad. = V(16.67)2 - 2x200X0:6 =) = 6:16 ms. so selative relocity of the automobile and the passenger ire the relocity with which the passenger crashes into the dashboard is s = unw=116.67 -6.16) w/s. I O'= 10.51 m/s