Why does a block of plastic released under water come up to the surface of water ?

In what direction does the buoyant force on an object immersed in a liquid act ?

A ball thrown up vertically returns to the thrower after 6s find. (a) the velocity with which it was thrown up. (b) the maximum height it reaches and (c) it's position after 4s.

A stone is allowed to fall from the top of a tower 100m high and at the same time another stone is projected vertically when and where the two stones will meet.

Calculate the force of gravitation between the earth and the sun, given that the mass of earth = 6 × 1024 kg. and of the sun = 2 × 1030 kg. The average distance between the two is 1.5 × 1011 m.

A stone is thrown vertically upward with an initial velocity of 40 m/s. Taking g = 10 m/s2 find the maximum height reached by the stone. What is the net displacement and the total distance covered by the stone ?