Question

A man of mass $50\text{kg}$ stands on a frame of mass $30\text{kg}$. He pulls on a light rope which passes over a pulley. The other end of the rope is attached to the frame. For the system to be in equilibrium, what force must the man exert on the rope? (Take $g=10{\text{m/s}}^2$)

• A. $400\text{N}$
• B. $374\text{N}$
• C. $418\text{N}$
• D. $448\text{N}$

Answer 1

The correct option is A $400\text{N}$

Force exerted by man on rope transfers to it in the form of tension.


Net upwards force on the system is $2F$.
Net downward force is $(50+30)g=80g$.
For equilibrium of system, $2F=80g$
or $F=40g=400\text{N}$