question_answer

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 will be       [CBSE PMT 1993; CPMT 1972, 75, 82; MP PMT 1996; AIEEE 2003]                    

A)                              P                     

B)                         \[\frac{Pm}{M+m}\]            

C)                         \[\frac{PM}{M+m}\]            

D)                           \[\frac{Pm}{M-m}\]

Correct Answer: C

Solution :

                                                  Acceleration of the system \[=\frac{P}{m+M}\]             The force exerted by rope on the mass \[=\frac{MP}{m+M}\]