Question

Two masses m and 2m are joined to each other by means of a frictionless pulley as shown below. When the mass 2m is released, the mass m will ascend with an acceleration of

• A. $\frac{g}{3}$
• B. $\frac{g}{2}$
• C. $g$
• D. $2g$

Answer 1

The correct option is A

$\frac{g}{3}$

From the second law of motion,
$2mg-T=2ma........\left(1\right)$
$T-mg=ma........\left(2\right)$
Adding equations (1) and (2), $mg=3ma\Rightarrow a=\frac{g}{3}$
Hence, the correct choice is (a).