CBSE Class 9 Physics Revision Worksheet

1- The school of a boy from his home is 1 km to the east. When he reaches back home, he says that he had traveled 2 km distance but his displacement is zero. Justify your answer.

2- Under what condition, the average speed is equal to the magnitude of the average velocity.

3- An object P is moving with a constant velocity for 5 mins. Another object Q is moving with changing velocity for 5 mins. Out of these two objects, which one has acceleration? Explain.

4- An electric train is moving with a velocity of 120km/hr. how much distance will it cover in30 sec?

5- A car is moving with a uniform velocity of 10m/s. the driver of the car decides to overtake the bus moving ahead of the car. So the driver of the car accelerates at 1m/s2 for 10 sec. Find the velocity of the car at the end of 10 sec. also find the distance traveled by the car while accelerating.

6- Give reasons:
(a) A passenger in a bus tends to fall backward when it starts suddenly.
(b) A bullet fired against a glass window pane makes a hole in it without cracking it.
(c) An athlete runs a certain distance before taking a long jump.

7- Explain with reasons:
a. When a shot is fired from a gun the gun recoils.
b. A jet aeroplane releases a lot of hot gases before taking off.
c. We press the ground while walking forward.
d. A rubber ball rebounds when struck against a hard floor.

8- What happens to the force of attraction between two objects when
(i) Their mass are halved?
(ii) Distance between them is increased to 4 times its previous value.
(iii) Distance between them as well as each of the mass is increase to 4 times.

9- If the distance between two bodies is increased 4 times by what factor should the mass of the bodies be altered so that the gravitational force between them remains the same?

10- What is the force between two spheres weighing 20 kg each and placed 50 cm apart?

11-  A sphere of mass 40 kg is attracted by another sphere of mass 15 kg when their centres are 0.2m apart with force of 9.8 x 10^-7 N. Calculate value of ‘G’.

12- A body weighs 1 kg on the surface of the moon. If mass of the moon is 7.4 x 10²² kg and radius of moon is 1740 km. Calculate:
a. The force acting between the body & the moon.
b. Acceleration produced in the body
c. Acceleration produced in moon.

13- A ball is thrown vertically upwards with a velocity of 49 m/s. Calculate:
(i) the max height to which it rises.
(ii) total time it takes to return to surface of the earth.

14- A stone is released from the top of a tower of height 19.6 m. Calculate the final velocity of a body just before touching the ground.

15- Differentiate between ‘g’ and ‘G’.

16- Name the factors on which ‘g’ depend.

17- Give a few examples / applications of the universal law of gravitation.

18- On what factor (s) does the gravity of a planet depend?

19- A stone is thrown vertically upwards with an initial velocity of 40m/s. Find the max height reached by the stone. What is the net displacement and the
total distance covered by the stone? [g = 10m/s²]

20- The object dropped from a height (h) with initial velocity zero strikes the ground with a velocity of 30m/s.
How long does it take to reach the ground. Also find h.(g = 10m/s²)

1. How will the equations of motion for an object moving with a uniform velocity change?

2. Obtain a relation for the distance travelled by an object moving with a uniform acceleration in the interval between 4th and 5th seconds.

3 On the earth, a stone is thrown from a height in a direction parallel to the earth’s surface while another stone is simultaneously dropped from the same height. Which stone would reach the ground first and why?

4. The weight of any person on the moon is about 1/6 times that on the earth. He can lift a mass of 15 kg on the earth. What will be the maximum mass, which can be lifted by the same force applied by the person on the moon?

5..Distinguish between mass and weight.

6. An object of mass 2 kg is sliding with a constant velocity of

4 m s^–1 on a frictionless horizontal table. The force required to keep the object moving with the same velocity is
(a) 32 N
(b) 0 N
(c) 2 N
(d) 8 N

7. water tanker filled up to2/3 of its height is moving with a uniform speed. On sudden application of the brake, the water in the tank would
(a) move backward
(b) move forward
(c) be unaffected
(d) rise upwards

8. The value of acceleration due to gravity
(a) is same on equator and poles
(b) is least on poles
(c) is least on equator
(d) increases from pole to equator

1-Define uniform uniform circular motion.

2-Deduce an equation for velocity-time relation. (v2-u2=2as)

3-Define force and give its units.

4-Define Newton’s first law of motion.

5-Define balanced and unbalanced forces.

6-A ball is gently dropped from a height of 20m if its velocity increases uniformly at the rate of 10m/s2.With what velocity will it strike the ground? After what time will it strike the ground?

7-What can you say about the motion of a body if its

a) displacement-time graph is a straight line passing through the origin?

b) velocity-time graph is parallel to the time axis?

1 MARK QUESTIONS

1. Nails and pins have pointed tips. Give reasons?

2. State Archimedes’ principle.

3. What will happen to the amount of work done if (a) the magnitude of force applied is increased. (b) the displacement of the body is reduced?

4. What is the work done on a body moving in a circular path?

5. Convert kwh into joules.

6. Why are sound waves called mechanical waves?

7. We cannot hear sound from the space. Why?

8. Why can we recognize our family members from their voice without seeing them?

9. What is meant by echocardiography?

10. What is the audible range of human ear?

2 MARK QUESTIONS

1. What is meant by reverberation? That are the measures taken to reduce reverberation?

2. Distinguish between longitudinal waves and transverse waves?

3. What happens to the kinetic energy of a body if the mass and velocity of the body are doubled?

4. When is the work done by a force in a body said to be negative? Give two examples.

5. A thrust of 200N exerts a pressure of 10Pa on a body. Calculate the area on which the pressure is exerted?

6. What is meant by echo? What are the conditions for the formation of an echo?

7. 8000 J of work is done by a machine to lift a mass of 100kg vertically upwards. Calculate the height to which the mass is lifted?

8. State the essential conditions needed for work to be done?

9. Derive the formula for gravitational potential energy.

10. Give the sequence of energy changes taking place in the production of electricity from a dam ?

3 MARKS QUESTIONS

1. An object of mass 80g has a volume of 20cm3. Will the object float on the water? Why? What will be the mass of water displaced by the object?

2. Give reasons:
a) Balloons filled with hydrogen rise to the ceiling.
b) Tractors have wide tyres.
c) A mug full of water appears light as long as it is under water in the bucket than when it is outside water.

3. State with reason whether work done is positive or negative in the following conditions : 
a) Work done by a man in lifting a bucket out of well by means of a pulley.
b) Work done by losing team in a tug of war.
c) Work done by an applied force on a body moving over a rough horizontal plane with uniform velocity.
d) Work done by a man in lifting a bucket out of well by means of a rope tied to a bucket
e) Work done by gravitational force in above case (d) .
f) Work done by gravity on a freely falling object.

4. What kind of energy transformations taking place in the following :
(i) Burning of fuels (ii) Photosynthesis (iii) Arrow released from stretched bows.

5. Define: (i) amplitude (ii) frequency (iii) wave length.

6. What is meant by kinetic energy? Derive an expression for kinetic energy?

7. 50 waves pass through a point in 0.1 second. If the distance between one crest and the adjacent through is 0.34m, calculate frequency, wave length and wave velocity.

8. The diagram shows two waveforms A and B. Downloaded from

(i) Which wave will have higher pitch? Give reasons.
(ii) Derive the relationship between wave velocity, frequency and wavelength?

9. How much will a body of weight 35N weigh in water if it displaces 1 litre of water ? (g = 9.8m/s²)

10. (i) Which wave property determines (a) loudness (b) amplitude?
(ii) Represent graphically (a) loud sound and soft sound. (b) high pitch and low pitch sound.

5 MARKS QUESTIONS.

State the law of conservation of energy. Illustrate the law by giving the example of a freely falling object.

1. a) Define power of a body . State and define the S.I unit of power.
b) Two children A and B both weighing 32kg start climbing up a rope separately and reach a height of 4m. A takes 10s and B takes 15s to reach that level. Calculate the amount of work done by A and B. Which of the two has more power? Show by calculation.

3. a) A body is floating on the surface of a liquid. With the help of a diagram show the two forces acting on it that are responsible for its floatation.
State the relationship between these two forces in this case?
b) What is relative density? If an object is immersed wholly in a liquid causing up thrust equal to the weight of the body then what will be the relation between the relative densities of liquid and the object?

4. a)State the relation between commercial unit of energy and S.I unit of energy.

1-Define the terms rest and motion. Give one example of each.

2-What is meant by uniform motion? Give one example.

3-When is a body said to have
a) uniform velocity?
b) uniform acceleration?

4-Distinguish between speed and velocity.

5-What do you mean by the term retardation? Give one example.

6-Deduce an expression for distance travelled by a body with a uniform acceleration in a given time.

7- Draw a distance-time graph of a body
a) moving with uniform velocity
b) moving with variable velocity.

8-A circular track has a circumference of 3140m with AB as one of its diameters. A scooter moves from A to B along a circular path with uniform speed of 10m/s.Find
a) distance covered by the scooterist
b) displacement of the scooterist
c) time taken by the scooterist in reaching from A to B.

9-Describe balanced and unbalanced forces.

10-State the various effects produced by a force.

11-State Newton’s three laws of motion.

12-What is the relationship between mass and inertia? Give the SI units of mass and inertia.

13-Define inertia of direction. Give one example.

14-Name the physical quantity which has the combined effect of mass and velocity and give its SI units.

15-A body of mass 5kg moving with a uniform velocity of 10m/s. It is acted upon by a force of 20N.What will be its velocity after 1s?

16-State Law of conservation of momentum.

17-A toy car of mass 250g is moving with a velocity of 5m/s. Find its momentum.

18-Distinguish between gravitation and gravity.

19-State Newton’s universal Law of gravitation , hence define universal gravitational constant. Give the value of G.

20-Calculate the force of gravitation between two bodies each of mass 70kg and placed 14cm apart. (Take G=6.67^-11Nm²/kg²)

1.Define the following terms

a) Rest

b) Motion

c) Distance

d) Displacement

e) speed

f) velocity

g) Acceleration

2.Differences between

a) Speed and velocity

b) Uniform and Non-uniform speed

c) Uniform and Non-uniform velocity

d) Uniform acceleration and non-uniform acceleration

3. Define Uniform circular motion

4. What do you mean by the term retardation? Give an example

5. Describe the distance-time graph for

a) Body at rest

b) Body moving with uniform velocity

c) Body moving with variable velocity

6. Derive the equation of motion for velocity-time retardation V = u + at

7.Derive the equation of motion for position-time relation S = ut + 1/2 at²

8.Derive graphically the position-velocity equation of motion v² - u² = 2as

9. A ball is dropped from a height of 50m. If its velocity increases uniformly at the rate of 10m/sec2

a) With what velocity will it strike the ground?

b) After what time will it strike the ground?

10. A car accelerating uniformly from 15m/sec to 20 m/sec in 8 sec. calculate

a) its acceleration

b)The distance covered by the car in that time.

11. Define the following terms

a) Force

b) Balanced forces.

c) Unbalanced forces.

d) Inertia

e) Inertia of rest

f) inertia of motion

g) inertia of direction

h) momentum

12. State the various effects produced by the force.

13. Define friction

14. State Newtons three law of motion

15. Explain the relationship between mass and inertia

16. calculate the force required to produce an acceleration of 7 m/sec² in a body of mass 85 kg.

17. State the law of conservation of momentum.