Science Do as directed; [1 M ]

The buoyant force on a boat is caused by the pressure of water ‘pushing up’ on the bottom of the boat.

Its weight varies; mass of an object is constant.

The body will float when dipped in a bucket of water as its density is less than that of water.

The mass of a body is more fundamental because mass of a body is constant and does not change from place to place.

Buoyant force or upthrust.

The upward force acting on an object immersed in a liquid is called upthrust.

The gravitational force is the source of the centripetal force that earth requires to revolve around the sun.

Reaction force.

Archimedes’ Principle.

Relative density is a dimensionless quantity and has no unit the ratio of the density (mass of a unit volume) of a substance to the density of a given reference material. Specific gravity usually means relative density with respect to water.

Gravitational force (exerted mainly by the moon and to some extent by the sun) is involved in the formation of tides in the sea.

An iron nail sinks in water but it floats in mercury because density of iron is more than that of water but less than that of mercury.

Gravitational force is responsible for the earth revolving round the sun.

The upward force exerted by any fluid (liquid, gas) on an object is known as upthrust or buoyancy.

Gravity of earth attracts every object towards its center. When an object is dropped from a certain height, it begins to fall towards Earth’s surface under the influence of gravitational force. Such a motion of object is called free fall.