Kids love to crash their toy cars together. One such collision involves a 0.5 kg car moving at 0.3 m/s colliding with a stationary toy car of mass 0.3 kg. The two toys stick together and move away from the collision point at 0.18 m/s. By what factor is the initial kinetic energy greater than the final kinetic energy

Factor of 2.08

Explanation:

Kinetic energy of defined as the energy possessed by a body by virtue of its motion. It is a function of tge velocity and mass of the object. Mathematically,

Kinetic energy = 1/2MV²

Where m is the mass of the object

V is the velocity

Taking m1 and m2 as the mass of the object

u1 and u2 is the velocities of the objects

The kinetic energy of the 0.5kg car moving with velocity 0.3m/s is

1/2 × 0.5 × 0.3²

= 0.0225Joules

The kinetic energy of the 0.3kg toy car moving with velocity 0m/s (since it is stationary) is;

1/2×0.3×0²

= 0Joules

Total kinetic energy of the bodies before collision = 0.0225+0 = 0.0225Joules.

Their kinetic energy after collision can be gotten using the formula;

KE = 1/2(m1+m2)v² where v is their common velocity

KE = 1/2(0.5+0.3)× 0.18²

KE = 1/2×0.8×0.18²

KE = 0.0108Joules

The ratio of the initial kinetic energy to the final kinetic energy will be 0.0225/0.0108 = 2.08

(KE)initial/(KE)final = 2.08

(KE)initial = 2.08(KE)final

This means the initial kinetic energy is greater than the final kinetic energy by a factor of 2.08

b.a device that inputs heat into a cool object