Question

On a level road , a motorcyclist applies brakes to slow down from a speed of 200kmph to 155 kmph. The mass of bike is 150 kg. Calculate the work done by the brakes?​

Answer 1

Answer:

Question

On a level road , a motorcyclist applies brakes to slow down from a speed of 200kmph to 155 kmph. The mass of bike is 150 kg. Calculate the work done by the brakes?

Answer

According to the question,

Total mass kg = 150 kg

Initial speed = 200 km/h = (200×1000)/3600 = 55.5556 m/s

Final speed = 155 km/h =(18×1000)/3600= 5 m/s

Work done by brakes =

(K.E)2 - (K.E)1

(1875-7500) J = -5625 J