When does an object float or sink when placed on the surface of water?
(i) An object sinks in water if its density is greater than that of water. Upthrust of water on an object is less than the weight of the object. Hence, it sinks.
(ii) An object floats on water when its density is less than that of water. When the upthrust of water on the object is greater than the weight of the object, the object floats.
What do you mean by buoyancy?
How does the force of gravitation between two bodies change when the distance between them is reduced to half?
Gravitational force acts on all objects in proportion to their masses. Why, then, does not a heavy object fall faster than a light object?
What is the magnitude of the gravitational force between the earth and 1 kg object on its surface? (Mass of the Earth = 6 x 104 kg and radius of earth is 6.4 x 106 m)
