Q110 / 150 · MHT CET 2024 (15 May Shift 2) · Physics
A particle of mass $m$ collides with another stationary particle of mass M . The particle m stops just after collision. The coefficient of restitution is .
- Correct answerA$\frac{m}{M}$
- B$\frac{M-m}{M+m}$
- C1
- D$\frac{\mathrm{m}}{\mathrm{M}+\mathrm{m}}$
Solution
Let v be the velocity of mass m and $\mathrm{v}^{\prime}$ be the velocity of mass M after collision.
By law of conservation of momentum, $\mathrm{mv}=\mathrm{Mv}^{\prime}$
$\therefore \quad \frac{\mathrm{v}^{\prime}}{\mathrm{v}}=\frac{\mathrm{m}}{\mathrm{M}}$
Coefficient of restitution $=\frac{\mathrm{v}_2-\mathrm{v}_1}{\mathrm{u}_1-\mathrm{u}_2}$ Here, $\mathrm{v}_1=0$ and $\mathrm{u}_2=0$ $\therefore \quad e=\frac{v^{\prime}}{v}=\frac{m}{M}$
Coefficient of restitution $=\frac{\mathrm{v}_2-\mathrm{v}_1}{\mathrm{u}_1-\mathrm{u}_2}$ Here, $\mathrm{v}_1=0$ and $\mathrm{u}_2=0$ $\therefore \quad e=\frac{v^{\prime}}{v}=\frac{m}{M}$
Hence, the correct answer is option: 'A'.