Question

A car of 500kg is moving with a velocity of 36km/h. When brakes are applied it stops with uniform negetive acceleration at a distance of 150m. Calculate the force applied by the brakes of the car & the work done before stopping it

Answer 1

Answer:

24750J

Explanation:

Mass of the car m 500 kg

Initial speed 36 km/h 10 m/s

Final speed v 0

s 150 m

We have v2 u2 2as

a (v2 - u2/(2s)

(0-102)/300 -100/300 = -0.33 m/s2

Retardation 0.33 m/s2

Force applied by the brakes Retarding force

F mass x retardation 500 x 0.33 165 N

Work done before stopping W Force x

distance moved= 165x 150= 24750 Nm

24750 J