A block of mass M slides down a frictionless plane inclined at an angle θ with the horizontal. The gravitational force on the block is directedGroup of answer choicestoward the center of mass of the block.perpendicular to the plane.parallel to the plane in the opposite direction as the movement of the blocktoward the center of the Earth.parallel to the plane in the same direction as the movement of the block.

A block of mass m is placed on a smooth inclined wedge ABC of inclination θ as shown in the figure. The wedge is given an acceleration 'a' towards the right. The relation between a and θ for the block to remain stationary on the wedge is :-    [2018]A: B: C: a = g cos θD: a = g tan θ

A block of mass m is placed on a smooth wedge of mass M placed at rest on a smooth horizontal surface as shown in the figure. During the time the block slides on the wedge,The centre of mass of the “block-wedge” system accelerates downward by acceleration a < g.Work done by the contact forces between block and wedge is zero in any frame.Momentum of the block-wedge system remains zero in horizontal direction.Work done by the contact forces between block and wedge is zero only in ground frame.

A block of mass 1 kg is pushed up a surface inclined to horizontal at an angle of 60∘ by a force of 10 N parallel to the inclined surface as shown in figure. When the block is pushed up by 10 m along inclined surface, the work done against frictional force is : [g=10 m/s2]

A block of mass m is placed on a smooth wedge of mass M. The value of force F such that m does not slide down relative to wedge is

A 10 kg block is placed on a horizontal surface whose coefficient of friction is 0.25. A horizontal force P = 15 N first acts on it in the eastward direction. Later, in addition to P a second horizontal force Q = 20 N acts on it in the northward direction : (Both east and west are in the plane of the fig and the gravity acts perpendicular to this plane )The block will not move when only P acts, but will be about to move when both P and Q actIf the block moves, the acceleration will be 0.5 m/s2.When the block moves, its direction of motion will be   (4/3) east of north When both P and Q act, the direction of the force of friction acting on the block will be   (3/4) west of      south