Question

A block of mass $M$ is pulled along a horizontal frictionless surface by a rope of mass $m$. If a force $P$ is applied at the free end of the rope, the force exerted by the rope on the block is

• A. $ \frac{Pm}{M+m} $
• B. $ \frac{Pm}{M-m} $
• C. $ P $
• D. $ \frac{PM}{M+m} $

Answer 1

Answer: (D)

The acceleration of the (rope + block) system is given by $a=\frac{P}{m+M}$.
Hence, the force on the block of mass $M$ is equal to $\left(\frac{M P}{m+M}\right)$