Question

In the system shown in figure $m_A=4kg,m_8=3kg$ and $m_c=8kg$. Friction is absent everywhere. A string is light and inextensible. If the system is released from rest find the acceleration of block B

• A. $\frac{g}{8}$
• B. $\frac{g}{2}$
• C. $\frac{g}{4}$
• D. $g$

Answer 1

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

When system is released from the position of rest then following are the eqns of motion,

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

and T = 3a - - - - - - - - - - -(2)

on adding eqns (1) and (2), we get,

7a = 4g

or a = $\frac{4g}{7}\approx \frac{8}{2}$

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