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## Homework Statement

A car, of mass 1100 kg, is travelling down a hill, inclined at an angle of 5

^{o}to the horizontal. The driver brakes hard and skids 15 m. The coefficient of friction between the tyres and the road is 0.7. Find the initial kinetic energy and speed of the car.

## Homework Equations

work done = force x displacement

weight of car down the hill = 1100 x 9.8 x sin 5

^{o}

normal reaction of road with car = 1100 x 9.8 x cos 5

^{o}

friction force = 0.7 x 1100 x 9.8 x cos 5

^{o}

## The Attempt at a Solution

I really do not know how to go about solving this. This braking hard and skidding has stumped me.