Question

Two bodies have their masses in the ratio $\frac{m_1}{m_2}=3$ and their kinectic energies in the ratio $\frac{E_1}{E_2}=\frac{1}{3}$. The ratio of their velocities is____ .

• A. 1 : 1
• B. 1 : 2
• C. 1 : 3
• D. 2 : 3

Answer 1

The correct option is C 1 : 3

$m_1/3=m_2$

$3E_1=E_2$

$E_1=0.5m_1{v}_1^2$

$E_2=3E_1=0.5m_2{v}_2^2=0.5\left(m_1/3\right)v_2^2$

$9E_1=0.5m_1{v}_2^2$

$\frac{v_1^2}{v_2^2}=\frac{1}{9}$

$\frac{v_1}{v_2}=\frac{1}{3}$