A pulley fixed to the ceilling carries a string with blocks of mass $m$ and $3 \,m$ attached to its ends. The masses of string and pulley are negligible. When the system is released, its centre of mass moves with what acceleration
A pulley fixed to the ceilling carries a string with blocks of mass $m$ and $3 \,m$ attached to its ends. The masses of string and pulley are negligible. When the system is released, its centre of mass moves with what acceleration
$0$
$g/4$
$g/2$
$ - g/2$
A pulley fixed to the ceilling carries a string with blocks of mass $m$ and $3 \,m$ attached to its ends. The masses of string and pulley are negligible. When the system is released, its centre of mass moves with what acceleration
$a=\frac{3 m g-m g}{3 m+m}=\frac{g}{2}$
$a_{c . m .}=\frac{m_1 a_1+m_2 a_2}{m_1+m_2}=\frac{3 m\left(\frac{g}{2}\right)+m\left(\frac{g}{2}\right)}{3 m+m}=\frac{g}{4}$