Question

Find the acceleration of block $A$ i.e. $a_A$ in the shown figure.

• A. $a_A=4{\text{m/s}}^2$, upwards
• B. $a_A=6{\text{m/s}}^2$, upwards
• C. $a_A=2{\text{m/s}}^2$, upwards
• D. $a_A=3{\text{m/s}}^2$, downwards

Answer 1

The correct option is A $a_A=4{\text{m/s}}^2$, upwards

Let the acceleration of the block $A$ be upwards and taking upward positive we have
For the pulley,
$a_P=\frac{a_B+a_A}{2}\Rightarrow 2=\frac{0+a_A}{2}\Rightarrow a_A=4{\text{m/s}}^2$
Hence, acceleration of block $A$ is $a_A=4{\text{m/s}}^2$, upwards.