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) Pm/(M+m)

(b) Pm/(M - m)

(c) P

(d) Pm/(M+m)

Answer 1

(d) : Acceleration of block (a) = (Force applied)/(Total mass)

or  a = P/(M + m)

Therefore, Force on block

= Mass of block x a = MP/(M + m).