A 5000kg car traveling at 40m/s crashes into a wall and comes to a complete stop in 10ms. What was the force on the wall?

20,000,000 N

Explanation:

First find the acceleration:

a = Δv / Δt

a = (0 - 40 m/s) / 0.010 s

a = - 4000 m/s²

Next use Newton's second law to find the force on the car:

F = ma

F = (5000 kg) (-4000 m/s²)

F = - 20,000,000 N

According to Newton's third law, the force on the wall is equal and opposite the force on the car.

F = 20,000,000 N