Question

A car is moving with a speed of 15kmper hour and another identical car is moving with a speed of 30km per hour.Compare their kinetic energy

Answer 1

Since Kinetic energy :

=1/2mv^2

Since both cars are identical hence there mass must be same

So both Kinetic energies can be compared as

2K.E./v^2 = 2K.E.'/v'^2

2K.E./225 = 2K.E.'/900

K.E./K.E.' = 225/900 = 1/4

Therefore both K.E are divided in the ratio of 1 : 4