Question:
A body A of mass $m$ is moving in a circular orbit of radius
$\mathrm{R}$ about a planet. Another body $\mathrm{B}$ of mass $\frac{\mathrm{m}}{2}$ collides with
A with a velocity which is half $\left(\frac{\vec{v}}{2}\right)$ the instantaneous
velocity $\vec{v}$ or A. The collision is completely inelastic. Then, the combined body:
Correct Option: , 4
Solution:
(4) From law of conservation of momentum, $\vec{p}_{i}=\vec{p}_{f}$
$m_{1} u_{1}+m_{2} u_{2}=M V_{f}$
$\Rightarrow v_{f}=\frac{\left(m v+\frac{m v}{4}\right)}{\frac{3 m}{2}}=\frac{5 v}{6}$
Clearly, $v_{f}