MCQ
A heavy body moving with a velocity of $6\,ms^{-1}$ collides elastically with a light body (whose mass is half of mass of heavy body) at rest. The velocity of light body will be (in $ms^{-1}$ )
- A$12$
- B$8$
- ✓$6$
- DVery large
✓
Answer
Correct option: C.
$6$
c
If $m$ and $M$ are the masses of light body and heavy body respectively, we have, according to law of conservation of momentum.
If $m$ and $M$ are the masses of light body and heavy body respectively, we have, according to law of conservation of momentum.
$\mathrm{M} \times 6+\mathrm{m} \times 0=\mathrm{M} \times 0+\mathrm{m} \times \mathrm{v}$
By $\operatorname{law}$ of conservation of $\mathrm{KE}$
$\frac{1}{2} M(6)^{2}=\frac{1}{2} m v^{2}$
Solving, we get $v=6 \mathrm{ms}^{-1}$
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