Question

A particle of mass $'m'$ moving with velocity $'v'$ collides in elastically with a stationary particle of mass $'2m'$. The speed of the system after collision will be

• A. $\frac{v}{2}$
• B. $2v$
• C. $\frac{v}{3}$
• D. $3v$

Answer 1

Answer: (C)

$\frac{v}{3}$

Answer 2

By the conservation of momentum

$mv + 2m \times 0 = 3mV$ ∴ $V = \frac{v}{3}.$