Question

An object of mass $m_1$ moving horiozntally with speed $u$ collides elastically with another object of mass $m_2$ at rest. Select correct statement.

• A. The momentum of the system is conserved only in direction $PQ$.
• B. Momentum of $m_1$ is conserved in direction perpendicular to $SR$.
• C. Momentum of $m_2$ will change in direction normal to $CR$.
• D. All of these.

Answer 1

The correct option is B Momentum of $m_1$ is conserved in direction perpendicular to $SR$.

As, we know linear momentum of individual particles remains unchanged along common tangent direction. Here, common tangent direction is perpendicular to the $SR\text{(which is common normal)}$.