Question

A Rod of length l and mass 4 m is hinged at one end as shown in Fig. A point mass m moving with a velocity v hits it on the other end and sticks. Find the angular velocity so formed. Assume the whole system is kept on a smooth horizontal table.

• A. $\frac{v}{5l}$
• B. $\frac{v}{3l}$
• C. $\frac{2v}{3l}$
• D. $\frac{3v}{7l}$

Answer 1

Answer: (D)

$\frac{3v}{7l}$

Answer 2

conserve angular momentum Iω =mv(l)

$\left( 4\frac{ml^{2}}{3} + ml^{2} \right)\omega = mvl$

or ω = $\frac{3v}{7l}$