Answer:
Four times as great.
Explanation:
The force of impact is given by the impulse
Impulse is the change in momentum of an object
u = Initial velocity of the car
v = Final velocity of the car = 0
m = Mass of the car
[tex]J=p_f-p_i\\\Rightarrow J=mv-mu\\\Rightarrow J=m(v-u)\\\Rightarrow J=mu[/tex]
When velocity is four times greater
[tex]J=4mu[/tex]
So, if velocity is increased 4 times the momentum will increase four times thus increasing the force of impact by four times.
