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Question
Two bodies have masses in the ratio 5 : 1 and their kinetic energies are in the ratio 125 : 9. Calculate the ratio of their velocities.
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Solution
Given `m_A/m_B = 5/1`
`K_A/K_B = 125/9`
Since `K_A/K_B = (1/2 m_A V_A^2)/(1/2 m_B V_B^2)`
= `(m_A/m_B)· V_A^2/V_B^2`
`125/9 = 5/1 ⋅ V_A^2/V_B^2 or V_A/V_B = sqrt(25/9)`
= `5/3`
Ratio of velocities of A and B is 5 : 3
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