Question

A triangular block $ABC$ of mass $m$ and sides $2a$ lies on a smooth horizontal plane as shown. Three point masses of mass $m$ each strikes the block at $A,B$ and $C$ with speeds $v$ as shown. After the collision the particle come to rest. Select the correct altemative(s)

• A. The centre of mass of $ABC$ remains stationary after collision
• B. The centre of mass of $ABC$ moves with a velocity valong $x$-axis after collision
• C. The triangular block rotates with an angular velocity $\omega =\frac{2\sqrt{3}mva}{I}$ about its centre of mass (here I is the moment of inertia of triangular block about its centroid axis perpendicular to its plane)
• D. A point lying at a distance of $\left(\frac{I}{2\sqrt{3}ma}\right)$ from G on perpendicular bisector of $BC$ (below $G$ ) is at rest just after collision.

Answer 1

Answer: (B)

by can scnation of liner momentum