Question

a plastic cube is released in water.will it sink or come to the surface of water,

Answer 1

The density of plastic is less than that of water, so the force of buoyancy on plastic block will be greater than the weight of plastic block displaced. Hence, the acceleration of plastic block will be in upward direction, and comes up to the surface of water.

Hope it helps u.

Answer 2

The plastic cube will not sink in water because the density of water is higher than the density of plastic cube. So the plastic cube will float in water.