(2) Mass of an irregular body can be measured by a spring balance.

(4) Density of only regular solids = Mass/Volume.

(5) Up-thrust happens to a body because its lower surface is at greater depth.

(6) Iron ball floats in mercury because density of iron is high.

(7) A brick weighs more in water than in air.

(8) Ice floats in water because density of water is less.

(9) Rules of floatation don’t apply to gases.

(10) When a liquid cools down its density increases.

(1) As per S.I. system the unit of density is kg m-3.

(3) The zero marking in a measuring cylinder is in the middle.

(1) Density bottles have a fixed ____________.

(3) Density of irregular solids = Mass / ____________.

(4) When a solid substance melts its density ____________.

(5) If a body has sunk in a liquid it means it’s up-thrust is ____________.

(6) If potato floats in water its density should be ____________.

(7) Buoyancy experienced by an iron ball in water is ____________ than in mercury.

(8) If a body has sunk in water its density must be ____________ than water.

(10) Relative density of iron is 7.5, it indicates it is ____________ denser than water.

(2) When a ball weighs A, in air and B, in water, it’s up-thrust will be ____________.

(9) It is easier to swim in the sea because it is ____________.

(2) Why is up-thrust so called?

(5) How can we identify a material by knowing its density?

(8) By composition the ice and water are the same; yet why does ice float in water?

(9) Why does an egg float in salt-water but not in tap water?

(1) What is the density of a substance?

(3) Describe usefulness of a density bottle.

(4) How do submarines sink and come back to the surface of the sea?

(6) In calculating the volume of a body when do we use a sinker?

(7) Among the three states of matter which has the lowest density?

(10) Will a body experience the same buoyancy in water and mustard oil?

(2) Name the factors on which the floating ability of a body depends.

(6) What is the connection between density and relative density?

(1) How can we calculate density of potato? Explain the steps.

(3) If a body sinks in water, is its apparent weight in water still less than its weight in air? Explain.

(4) Why is it easier for us to swim in the sea than in the river?

(5) Explain how a ship floats in water but an iron nail sinks.

(7) Why do certain objects float in water while others do not?

(8) Up thrust depends on the difference in forces acting on the upper and the lower surface of a body. Explain.

(9) Explain why force of buoyancy is more in mercury than in water for the same iron ball?

Weight of the displaced liquid

Same for both the cubes

The mass of substance with lower density will be more

Four degree Celsius

Weight of the displaced liquid

by using a liquid in which it is insoluble

Balloons of same volume filled with air or hydrogen will have same up-thrust.

Body having lower density will have greater volume

It is the final weight of body in the fluid.

None of the above

by using a liquid in which it is insoluble

Stay stable beneath the surface of the liquid