Question

Mass pulley system is shown in figure. The string is massless. One end of the string is pulled by the force $F=2mg$. The acceleration of the block will be (mass of pulley is $m$).

• A. $g/2$
• B. $0$
• C. $g$
• D. $3g$

Answer 1

The correct option is D $3g$

Force is applied on the $2nd$ rope is $2mg$ so the tension developed is $2mg.$

So$,$ the net tension on $1st$ rope will be $2T$ that is $2\times mg=4mg$

$4mg-mg=ma$

$a=3g$

Hence,

option $\left(D\right)$ is correct answer.