A block of mass $M$ is pulled along a horizontal frictionless surface by a rope of mass $m$. If a force $F$ is applied at one end of the rope, the force which the rope exerts on the block is 

In the figure, mass $M=10 \mathrm{g}$ is placed on an inclined plane. In order to keep it at rest, the value of mass $m$ will b

A block is dragged on a smooth plane with the help of a rope which moves with a velocity $v$ as shown in figure. The horizontal velocity of the block is

In the figure the ends P and Q of an unstrechable string move downward with uniform speed v. Mass M moves upwards with speed.