Sand is being dropped on a conveyer belt at the rate of M kg/s. The force necessary to keep the belt moving with a constant velocity of $$\upsilon $$ m/s will be :

Three forces acting on a body are shown in the figure. To have the resultant force only along the y-direction, the magnitude of the minimum additional force needed is

A block B is pushed momentarily along a horizontaly surface with an initial velocity V. If  $$\mu $$  is the coefficient of sliding friction between B and the surface, block B will come to rest after a time

The coefficient of static friction, $$\mu $$_s, between block A of mass 2 kg and the table as shown in the figure is 0.2. What would be the maximum mass value of block B so that the two blocks do not move? The string and the pulley are assumed to be smooth and massless. (g = 10 m/s²)