English Medium कक्षा ९ - CBSE Question Bank Solutions

Write down an equation that defines density.

5 kg of material A occupy 20 cm³ whereas 20 kg of materia! B occupy 90 cm³. Which has the greater density : A or B ? Support your answer with calculations.

Define density. What is the SI unit of density ?

Define relative density. What is the SI unit of relative density ?

The density of turpentine is 840 kg/m³. What will be its relative density ? (Density of water = 1000 kg/m³)

A piece of steel has a volume of 12 cm³, and a mass of 96 g. What is its density in g/cm³ ?

A body floats in kerosene of density 0.8 x 10³ kg/m³ up to a certain mark. If the same body is placed in water of density 1.0 x 10³ kg/m³, will it sink more or less ? Give reason for your answer.

When a golf ball is lowered into a measuring cylinder containing water, the water level rises by 30 cm³ when the ball is completely submerged. If the mass of ball in air is 33 g, find its density.

A piece of steel has a volume of 12 cm³, and a mass of 96 g. What is its density in kg/m³ ?

According to the third law of motion, action and reaction :

An object is put in three liquids having different densities, one by one. The object floats with `1/9` , `2/11` and `3/7` parts of its volume outside the surface of liquids of densities d₁, d₂ and d₃ respectively. Which of the following is the correct order of the densities of the three liquids?

A metal in which even iron can float is :

The relative densities of four liquids P, Q, R and S are 1.26, 1.0, 0.84 and 13.6 respectively. An object is floated in all these liquids, one by one. In which liquid the object will float with its maximum volume submerged under the liquid?

A solid of density 900 kg/m³ floats in oil as shown in the given diagram. The oil floats on water of density 1000 kg/m³ as shown. The density of oil kg/m³ could be :

The density of water is 1000 kg/m3 and the density of copper is 8900 kg/m3. Which of the following statements is incorrect?

The diagrams represent four measuring cylinders containing liquids. The mass and volume of the liquid in each cylinder are stated. Which two measuring cylinder could contain an identical liquid?

Calculate the work done by the brakes of a car of mass 1000 kg when its speed is reduced from 20 m/s to 10 m/s?

A body of mass 100 kg is lifted up by 10 m. Find :
(i) the amount of work done
(ii) potential energy of the body at that height (value of g = 10 m/s²)

How much is the mass of a man if he has to do 2500 joules of work in climbing a tree 5 m tall? (g = 10 m s⁻²)