Question

How far from the midpoint of the stick is the center of mass of the stick-puck combination after the collision?

• A. $\frac{l}{2}$
• B. $\frac{l}{3}$
• C. $\frac{l}{4}$
• D. None of these

Answer 1

The correct option is C $\frac{l}{4}$

The distance of center of mass of system from the mid point of rod after the collision

$=\frac{m_1{r}_1+m_2{r}_2}{m_1+m_2}$

$=\frac{m\left(0\right)+m\left(\frac{l}{2}\right)}{m+m}$

$=\frac{l}{4}$