Question

A mass $m$ hangs with the help of a string wrapped around a pulley on a frictionless bearing. The pulley has mass $m$ and radius $R$. Assuming pulley to be a perfect uniform circular disc, the acceleration of the mass $m$, if the string does not slip on the pulley, is

• A. $\frac{g}{3}$
• B. $\frac{3}{2} g$
• C. $g$
• D. $\frac{2}{3} g$

Answer 1

Answer: (D)

$\frac{2}{3} g$

Answer 2

$a=\frac{m g}{m+\frac{I}{R^{2}}}=\frac{m g}{m+\frac{m}{2}}=\frac{2 g}{3}$