At a race track, a car of mass 1150 kg crashes into a concrete wall at a speed of 85 m/s a. If the car comes to a stop when it hits the wall, what the magnitude of the impulse applied to the car? The car crashed into the wall, stopping in 0.1 seconds. What force is applied to the car?

Question

Randy

Physics

2 September, 16:34

At a race track, a car of mass 1150 kg crashes into a concrete wall at a speed of 85 m/s a. If the car comes to a stop when it hits the wall, what the magnitude of the impulse applied to the car? The car crashed into the wall, stopping in 0.1 seconds. What force is applied to the car?

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Javion Small · Answer 1

This is a momentum / impulse question. Δp = F• (Δt)

The momentum of the car goes from 1150*85 = 97750 to 0 in 0.1 seconds.

From this we get the equation 97750 = F (.1)

a) F = 977500 N

For part b), the change in momentum is unchanged, so we must increase the time in order to decrease the force.

97750 = 200000 (t)

b) t = 0.49 s or. 5 s considering sig figs which means an increase factor of 5