Question

A partical of mass $2m$ moving with velocity $v$ strikes a stationary particle of mass $3m$ and sticks to it. The speed of the system will be

• A. $0.8v$
• B. $0.2v$
• C. $0.6v$
• D. $0.4v$

Answer 1

The correct option is D $0.4v$

Let speed after collision is $v_1$.

There is no external force acting on the system, Linear momentum will be conserved.

$\therefore$ Linear momentum before collision = Linear momentum after collision

$\Rightarrow 2mv=(2m+3m)v_1$ $\Rightarrow v_1=\frac{2}{5}=0.4v$