Q2 of 16 Page 25

A body which floated in water, sank when put in kerosene. Why did it happen?

A body floats in a liquid when the buoyant force (weight of displaced liquid) is more than or equal its weight in air. There’s a net force in the upward direction. The opposite happens when a body sinks, the weight of the liquid displaced is less than the weight of the body in air. Kerosene is less dense than water. So the same body displaces a greater weight of water than of kerosene, and hence floats in water but sinks in kerosene. The buoyancy is greater in water than in kerosene for a given body.


More from this chapter

All 16 →
1

The weight of a piece of stone in air is 120 N and its weight in water is 10 N. Calculate the buoyancy, experienced by the stone.

 3

Observe the figures of an object placed in different liquids.


a. Compare the gravitational force and the buoyance acting on the body when it is in the liquids A, B and C.


b. If the body is a solid substance, which is the liquid whose density is equal to that of the solid?

 4

A body of weight 1000 N sinks in water. The weight of the liquid overflowed is 250 N.

What will be the weight of the body in water?

 4

A body of weight 1000 N sinks in water. The weight of the liquid overflowed is 250 N.

A body of the same weight as above floats in water. What is its weigh in water? What will be the weight of the water displaced?