Question

A car is travelling at 31.5 km/hr near a school zone. When the driver sees a
child crossing the road 40 metres away, the driver applies the brake and
skids to a stop. The resulting deceleration of the car is given as -2.21 m/s .
How long will it take for the car to come to rest (30 marks)?
How far will the car skid (30 marks) ?
Discuss the results and write a brief conclusion in relation to the
safety of the child (40 marks; max 300 words).
2
31.5 km/hr * 1000m/km * 1hr/3600s = 8.75 m/s
so, at -2.21 m/s^2, that means it takes 8.75/2.21 = 3.96 seconds to stop
s = 8.75*3.96 - 2.21/2 * 3.96^2 = 17.32 meters

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