Question

The speed of a vehicle of mass 500 kg increases from 36 km/h to 72 km/h. Calculate

the increase in its kinetic energy.?​

Answer 1

Change in Kinetic Energy =1/2m((v1)^2-(v2)^2)).....................(1)
where m is mass of vehicle, vf is final speed and vi is initial speed.

we have vf = 72 km/h = 72×(5/18) = 20 m/s and vi = 36 km/h = 10 m/s

Change in kinetic energy = (1/2)×500×((20)^2- (10)^2)
= 75 kJ