Question

Two objects having equal masses are moving with uniform velocities of 2 m/s and 6 m/s respectively. Calculate the ratio of their kinetic energies.

Answer 1

Let the masses of the two bodies be (m₁) = m kg and (m₂) = m kg.
Velocity of the first body, (v₁) = 2 m/s
Velocity of the first body, (v₂) = 6 m/s
The required ratio is-
= `("kinetic energy")_1/("Kinetic energy")_2`
= `(1/2(m_1) (v_1)^2)/(1/2(m_2) (v_2)^2)`
= So , put the values to get the ratio , 
= `(2)^2/(6)^2`
= `1/9`

The ratio of the kinetic energies is, K.E of body 1 : K.E of body 2 = 1 : 9