Question

Three blocks with masses $m,2m$ and $3m$ are connected by strings, as shown in the figure. After an upward force $F$ is applied on block $m$, the masses move upward at constant speed $v$. What is the net force on the block of mass $2m$?
($g$ is the acceleration due to gravity)

• A. $\text{Zero}$
• B. $2\text{mg}$
• C. $3\text{mg}$
• D. $6\text{mg}$

Answer 1

The correct option is A $\text{Zero}$

All blocks are moving with constant velocity. So, net force on all blocks is zero