Question

In the system shown in figure $m_A=4m,m_B=3m$ and $m_C=8m$. Friction is absent everywhere. String is light and in-extensible. If the system is released from rest find the acceleration of block B

• A. $\frac{g}{8}$ (leftward)
• B. $\frac{g}{2}$ (leftward)
• C. $\frac{g}{6}$ (rightward)
• D. $\frac{g}{4}$ (rightward)

Answer 1

The correct option is B $\frac{g}{2}$ (leftward)

When the system is released from the position of rest, the equations of motions are given as,

$4a=4g-T$ (1)

$T=3a$ (2)

From the equation (1) and (2) it can be written as,

$7a=4g$

$a=\frac{4g}{7}$

$a\approx \frac{g}{2}$

Thus, the acceleration of block B is $\frac{g}{2}$ towards the left side.