# physics

posted by Nukhba

a car of mass 12,000 kjg is moving at 40m/s along a strong road. The driver brakes and the car goes 800 meters before stopping. What was the magnitude of the average force of friction (inN) between tires and road?

1. Damon

Is the mass a typo?
12,000 kg is too big for a car

force * distance = change in kinetic energy

800 F = (1/2)(12,000 ?)(1600)

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