Question

3. When a vehicle of total mass 1 600 kg was brought to rest on a level road by braking,
500 kJ of heat were produced. Find the speed of the vehicle just before the brakes were
applied.

Answer 1

Explanation:

3. When a vehicle of total mass 1 600 kg was brought to rest on a level road by braking,

500 kJ of heat were produced. Find the speed of the vehicle just before the brakes were

applied.

Answer 2

Answer:

Here we use law of conservation of energy.

firstly the vehicle has kinetic energy when that was moving and after applying breaks the kinetic energy converted into heat

So K.E=Heat produced while breaking

1/2*m*v^2=500*1000J

1/2*1600*v^2=500000

v^2=625

v=√(625)

v=25

Hence the speed of vehicle just before the breaks applied was 25 m/s