Question

If two bodies, one light and other heavy have equal kinetic energies, which one has a greater momentum?

• A. Heavy body
• B. Light body
• C. Both have equal momentum
• D. It depends on the actual velocities

Answer 1

The correct option is B Light body

$K.E_1=\frac{1}{2}{m}_1{v}_1^2$

$K.E_2=\frac{1}{2}{m}_2{v}_2^2$

Given that

$K.E_1=K.E_2$

$m_1{v}_1^2=m_2{v}_2^2$

$\frac{m_1^2{v}_1^2}{m_1}=\frac{m_2^2{v}_2^2}{m_2}$

$\frac{m_1{v}_1}{m_2{v}_2}=\sqrt{\frac{m_1}{m_2}}=\sqrt{\frac{2}{8}}=\frac{1}{2}=0.5$