(English Medium) ICSE Class 9 - CISCE Question Bank Solutions

Describe an experiment to demonstrate that air exerts pressure.

What is an aneroid barometer?
Draw a neat and labeled diagram to explain its construction and working.

In the Figure a block of weight 15 N is hanging from a rigid support by a string. What force is exerted by (a) a block on the string and (b) a string on the block? Name and show them in the diagram.

What do you understand by the term force due to gravity ? 

The weight of a body on Earth is 98 N, where acceleration due to gravity is 9.8 m s^-2. What will be its (a) mass and (b) weight on the Moon, where acceleration due to gravity is 1.6 m s^-2?

What is the (a) force of gravity and (b) weight of a block of mass 10.5 kg ? Take g = 10 ms^-2 .

Assuming the density of air to be 1.295 kg m^-3, find the fall in barometric height in mm of Hg at a height of 107 m above the sea level. Take density of mercury = 13.6 × 10³ kg m^-3.

A body dipped into a liquid experiences an upthrust. State two factors on which upthrust on the body depends. 

A body of density ρ is immersed in a liquid of density ρ_L. State the condition when the body will (i) float and (ii) sink in the liquid. 

A body held completely immersed inside a liquid experiences two forces:

(i) F₁, the force due to gravity and

(ii) F₂, the buoyant force.

Draw a diagram showing the direction of these forces acting on the body and state the condition when the body will float or sink. 

Complete the following sentence :

An empty tin container with its mouth closed has an average density equal to that of a liquid. The container is taken 2 m below the surface of that liquid and is left there. Then the container will ____________ .

A bunch of feathers and a stone of the same mass are released simultaneously in air. Which will fall faster and why? How will your observation be different if they are released simultaneously in vacuum?

A body of density ρ sinks in a liquid of density ρ_L.  The densities ρ and ρ_L are related as :

A body of volume 100 cm³ weighs 5 kgf in air. It is completely immersed in a liquid of density 1.8 × 10³ kg m^-3. Find:

1. The upthrust due to liquid and
2. The weight of the body in liquid. 

A piece of brass weighs 175 gf in air and 150 gf when fully submerged in water. The density of water is 1.0 g cm^-3.

(i) What is the volume of the brass piece? (ii) Why does the brass piece weigh less in water? 

Define the term density.