A car of mass 1000kg is travelling at 20m/s when it

collides with a wall.

The front of the car collapses in 0.1 seconds,

by which time the car is at rest.

Calculate the deceleration of the car.

Calculate the force exerted by the wall on the car.

Deceleration=200m/s^2

Force = - 2 * 10^5

Explanation:

initial velocity u = 20m/s final velocity v = 0m/s time t = 0.1s

v = u + at

0 = 20 + 0.1a

0-20 = 0.1a

-20/0.1 = 0.1a/0.1

a = - 20/0.1

a = - 200m/s^2

F = m (v-u) / t

F = 1000 (0-20) / 0.1

F=1000 * - 20/0.1

F=1000 * - 200

F = - 2 * 10^5N