Question

In the system shown, block $A$ is of mass $4.0kg$ and blocks $B$ and $C$ are of equal mass each of $3kg$. Find the acceleration in $m/s^2$ of block $C$, if the system is set free. $[g=10m/s^2$ ]

Answer 1

Answer: 2

$F.B.D$. of the blocks $A,B$ and $C$

Conditions of forces on $B$ and $C$ are same so they both will move with same downward acceleration $a$.
The block $A$ moves with the same acceleration $a$ upwards
From block $A:2T-40=4a$ ...(i)
From block $B$ or $C:30-T=3a$ ...(ii)
From above two equations $a=2m/s^2$