1) A particle of mass 9kg is sliding down a smooth inclined plane with an acceleration of 4.9m per second per second. Find the angle of inclination of the plane.

2) A parcel of mass 60kg is released from rest on a smooth plane inclined at arcsin3/5 to the horizontal. Find the velocity of the parcel when it has travelled 5m down the plane.

3) A horizontal force of 2N is just sufficient to prevent a block of mass 1kg from sliding down a rough plane inclined at arcsin 7/25 to the horizontal. Find the coefficient of friction between the block and the plane and the acceleration with which the block will move when the force is removed.

4) A stone slides in a straight line across a frozen pond. Given that the initial speed of the stone is 5m per second and that it slides 20m before coming to rest, calculate the coefficient of friction between the stone and the surface of the frozen pond.

Any help would be much appreciated. Thanks in advance.