Question

A 1200 kg test car is traveling at 25 m/s when it crashes head on into a wall and comes to a stop. if the time of impact is 0.04 s, what is the force acting on the car?

Answer 1

Given:

m(mass of the car)=1200 Kg

u(initial velocity)=25m/s

Time of impact=0.04s

v(final velocity)=0.

Now we know that

v=u +at

Where v is the final velocity

u is the initial velocity

a is the acceleration

t is the time of impact

Substituting these values we get

0=25+ax0.04

-0.04 a =25

a=-625 m/s^2

Now we also know that

F=mxa

Where F is the force

m is the mass of the car

a is the acceleration of the car

F=1200 x 625

F=750000N