# Lakhmir Singh solutions for Science Class 9 Physics chapter 1 - Motion [Latest edition]

#### Chapters ## Chapter 1: Motion

### Lakhmir Singh solutions for Science Class 9 Physics Chapter 1 Motion Very Short Answers, Short Answers, Long Answers, MCQ, Hots Questions [Pages 19 - 22]

Very Short Answers | Q 1 | Page 19

Is displacement a scalar quantity ?

Very Short Answers | Q 2 | Page 19

State whether distance is a scalar or a vector quantity.

Very Short Answers | Q 3 | Page 19

Change the speed of 6 m/s into km/h.

Very Short Answers | Q 4 | Page 19

What name is given to the speed in a specified direction ?

Very Short Answers | Q 5 | Page 19

Give two examples of bodies having non-uniform motion.

Very Short Answers | Q 6 | Page 19

Name the physical quantity obtained by dividing ‘Distance travelled’ by ‘Time taken’ to travel that distance.

Very Short Answers | Q 7 | Page 19

What do the following measure in a car ?
(a) Speedometer (b) Odometer

Very Short Answers | Q 8 | Page 20

Name the physical quantity which gives us an idea of how slow or fast a body is moving.

Very Short Answers | Q 9 | Page 20

Under what conditions can a body travel a certain distance and yet its resultant displacement be zero ?

Very Short Answers | Q 10 | Page 20

In addition to speed, what else should we know to predict the position of a moving body ?

Very Short Answers | Q 11 | Page 20

When is a body said to have uniform velocity ?

Very Short Answers | Q 12 | Page 20

Under which condition is the magnitude of average velocity equal to average speed ?

Very Short Answers | Q 13 | Page 20

Which of the two can be zero under certain conditions : average speed of a moving body or average velocity of a moving body ?

Very Short Answers | Q 14 | Page 20

Give one example of a situation in which a body has a certain average speed but its average velocity is zero.

Very Short Answers | Q 15 | Page 20

What is the acceleration of a body moving with uniform velocity ?

Very Short Answers | Q 16 | Page 20

What is the other name of negative acceleration ?

Very Short Answers | Q 17 | Page 20

Name the physical quantity whose SI unit is :
(a) m/s (b) m/s2

Very Short Answers | Q 18 | Page 20

What type of motion is exhibited by a freely falling body ?

Very Short Answers | Q 19 | Page 20

What is the SI unit of retardation ?

Very Short Answers | Q 20.1 | Page 20

Fill in the following blank with suitable word :

Displacement is a…………………… quantity whereas distance is a………………………….

Very Short Answers | Q 20.2 | Page 20

Fill in the following blank with suitable word:

The physical quantity which gives both, the speed and direction of motion of a body is called its……………

Very Short Answers | Q 20.3 | Page 20

Fill in the following blank with suitable word :

A motorcycle has a steady……………. of 3 m/s2. This means that every………………. its…………….. increases by………….

Very Short Answers | Q 20.4 | Page 20

Fill in the following blank with suitable word :

Velocity is the rate of change of……………………… It is measured in.............. .

Very Short Answers | Q 20.5 | Page 20

Fill in the following blank with suitable word :

Acceleration is the rate of change of………………. It is measured in..............

Short Answers | Q 21 | Page 20

What type of motion, uniform or non-uniform, is exhibited by a freely falling body ? Give reason for your answer.

Short Answers | Q 22 | Page 20

State whether speed is a scalar or a vector quantity. Give reason for your choice.

Short Answers | Q 23 | Page 20

Bus X travels a distance of 360 km in 5 hours whereas bus Y travels a distance of 476 km in 7 hours. Which
bus travels faster ?

Short Answers | Q 24.1 | Page 20

Arrange the following speed in increasing order (keeping the least speed first):

An athlete running with a speed of 10 m/s.

Short Answers | Q 24.2 | Page 20

Arrange the following speed in increasing order (keeping the least speed first):

A bicycle moving with a speed of 200 m/min.

Short Answers | Q 24.3 | Page 20

Arrange the following speed in increasing order (keeping the least speed first

A scooter moving with a speed of 30 km/h.

Short Answers | Q 25.1 | Page 20

Write the formula for acceleration. Give the meaning of each symbol which occurs in it.

Short Answers | Q 25.2 | Page 20

A train starting from Railway Station attains a speed of 21 m/s in one minute. Find its acceleration.

Short Answers | Q 26.1 | Page 20

What term is used to denote the change of velocity with time ?

Short Answers | Q 26.2 | Page 20

Give one word which means the same as ‘moving with a negative acceleration’.

Short Answers | Q 26.3 | Page 20

The displacement of a moving object in a given interval of time is zero. Would the distance travelled by the object also be zero ? Give reason for your answer.

Short Answers | Q 27 | Page 20

A snail covers a distance of 100 metres in 50 hours. Calculate the average speed of snail in km/h.   Short Answers | Q 28 | Page 21

A tortoise moves a distance of 100 metres in 15 minutes. What is the average speed of tortoise in km/h ?

Short Answers | Q 29 | Page 21

If a sprinter runs a distance of 100 metres in 9.83 seconds, calculate his average speed in km/h.

Short Answers | Q 30 | Page 21

A motorcyclist drives from place A to B with a uniform speed of 30 km h-1 and returns from place B to A with a uniform speed of 20 km h-1. Find his average speed.

Short Answers | Q 31 | Page 21

A motorcyclist starts from rest and reaches a speed of 6 m/s after travelling with uniform acceleration for 3 s. What is his acceleration ?

Short Answers | Q 32 | Page 21

An aircraft travelling at 600 km/h accelerates steadily at 10 km/h per second. Taking the speed of sound as 1100 km/h at the aircraft’s altitude, how long will it take to reach the ‘sound barrier’ ?

Short Answers | Q 33 | Page 21

If a bus travelling at 20 m/s is subjected to a steady deceleration of 5 m/s2, how long will it take to come to rest ?

Long Answers | Q 34.1 | Page 21

What is the difference between distance travelled  by a body and its displacement ? Explain with the
help of a diagram.

Long Answers | Q 34.2 | Page 21

An ant travels a distance of 8 cm from P to Q and then moves a distance of 6 cm at right angles to PQ. Find its resultant displacement.

Long Answers | Q 35 | Page 21

Define motion. What do you understand by the terms uniform motion and non-uniform motion ? Explain with examples.

Long Answers | Q 36.1 | Page 21

Define speed. What is the SI unit of speed ?

Long Answers | Q 36.2 | Page 21

What is meant by average speed?

Long Answers | Q 36.3 | Page 21

What is meant by uniform speed ?

Long Answers | Q 37.1 | Page 21

Define velocity. What is the SI unit of velocity ?

Long Answers | Q 37.2 | Page 21

What is the Differnece between speed and velocity ?

Long Answers | Q 37.3 | Page 21

Convert a speed of 54 km/h into m/s.

Long Answers | Q 38.1 | Page 21

What is meant by the term acceleration ? State the SI unit of acceleration.

Long Answers | Q 38.2 | Page 21

Define the term uniform acceleration. Give one example of a uniformly accelerated motion.

Long Answers | Q 39 | Page 21

The distance between Delhi and Agra is 200 km. A train travels the first 100 km at a speed of 50 km/h. How fast must the train travel the next 100 km, so as to average 70 km/h for the whole journey ?

Long Answers | Q 40 | Page 21

A train travels the first 15 km at a uniform speed of 30 km/h; the next 75 km at a uniform speed of 50 km/h; and the last 10 km at a uniform speed of 20 km/h. Calculate the average speed for the entire train journey.

Long Answers | Q 41.1 | Page 21

A car is moving along a straight road at a steady speed. It travels 150 m in 5 seconds:

What is its average speed ?

Long Answers | Q 41.2 | Page 21

A car is moving along a straight road at a steady speed. It travels 150 m in 5 seconds:

How far does it travel in 1 second ?

Long Answers | Q 41.3 | Page 21

A car is moving along a straight road at a steady speed. It travels 150 m in 5 seconds:
How far does it travel in 6 seconds ?

Long Answers | Q 41.4 | Page 21

A car is moving along a straight road at a steady speed. It travels 150 m in 5 seconds:

How long does it take to travel 240 m ?

MCQ | Q 42 | Page 21

A particle is moving in a circular path of radius r. The displacement after half a circle would be :

• 0

• pir

• 2r

• 2pir

MCQ | Q 43 | Page 21

The numerical ratio of displacement to distance for a moving object is :

• always less than 1

• equal to 1 or more than 1

• always more than 1

• equal to 1 or less than 1

MCQ | Q 44 | Page 21

A boy is sitting on a merry-go-round which is moving with a constant speed of 10 m s−1. This means that the boy is :

• at rest

• moving with no acceleration

• in accelerated motion

• moving with uniform velocity

MCQ | Q 45 | Page 21

In which of the following cases of motion, the distance moved and the magnitude of displacement are equal?

•  if the car is moving on straight road

•  if the car is moving on circular road

• if the pendulum is moving to and fro

•  if a planet is moving around the sun

MCQ | Q 46 | Page 21

The speed of a moving object is determined to be 0.06 m/s. This speed is equal to :

• 2.16 km/h

• 1.08 km/h

• 0.216 km/h

• 0.0216 km/h

MCQ | Q 47 | Page 22

A freely falling object travels 4.9 m in 1st second, 14.7 m in 2 nd second, 24.5 m in 3rd second, and so on. This data shows that the motion of a freely falling object is a case of :

• uniform motion

• uniform acceleration

• no acceleration

• uniform velocity

MCQ | Q 48 | Page 22

When a car runs on a circular track with a uniform speed, its velocity is said to be changing. This is because :

• the car has a uniform acceleration

• the direction of car varies continuously

• the car travels unequal time intervals.

• the car travels equal distances in unequal time intervals

MCQ | Q 49 | Page 22

Which of the following statement is correct regarding velocity and speed of a moving body?

• velocity of a moving body is always higher than its speed

• speed of a moving body is always higher than its velocity

• speed of a moving body is its velocity in a given direction

• velocity of a moving body is its speed in a given direction

MCQ | Q 50 | Page 22

Which of the following can sometimes be 'zero' for a moving body?
(i) average velocity
(ii) distance travelled
(iii) average speed
(iv) displacement

• only (i)

• (i) and (ii)

• (i) and (iv)

•  only (iv)

MCQ | Q 51 | Page 22

When a car driver travelling at a speed of 10 m/s applies brakes and brings the car to rest in 20 s, then retardation will be :

• + 2 m/s2

• − 2 m/s2

• − 0.5 m/s2

• + 0.5 m/s2

MCQ | Q 52 | Page 22

Which of the following could not be a unit of speed?

•  km/h

• s/m

• m/s

• mm s−1

MCQ | Q 53 | Page 22

One of the following is not a vector quantity. This one is :

• displacement

• speed

• acceleration

• velocity

MCQ | Q 54 | Page 22

Which of the following could not be a unit of acceleration?

• km/s2

• cm s−2

• km/s

• m/s2

Hots Questions | Q 55 | Page 22

A body is moving along a circular path of radius R. What will be the distance travelled and displacement of the body when it completes half a revolution ?

Hots Questions | Q 56.1 | Page 22

If on a round trip you travel 6 km and then arrive back home :

What distance have you travelled ?

Hots Questions | Q 56.2 | Page 22

If on a round trip you travel 6 km and then arrive back home :

What is your final displacement ?

Hots Questions | Q 57.1 | Page 22

A body travels a distance of 3 km towards East, then 4 km towards North and finally 9 km towards East.

What is the total distance travelled ?

Hots Questions | Q 57.2 | Page 22

A body travels a distance of 3 km towards East, then 4 km towards North and finally 9 km towards East.

What is the resultant displacement ?

Hots Questions | Q 58 | Page 22

A boy walks from his classroom to the bookshop along a straight corridor towards North. He covers a distance of 20 m in 25 seconds to reach the bookshop. After buying a book, he travels the same distance in the same time to reach back in the classroom. Find (a) average speed, and (b) average velocity, of the boy.

Hots Questions | Q 59 | Page 22

A car travels 100 km at a speed of 60 km/h and returns with a speed of 40 km/h. Calculate the average speed for the whole journey.

Hots Questions | Q 60 | Page 22

A ball hits a wall horizontally at 6.0 m s-1. It rebounds horizontally at 4.4 m s-1. The ball is in contact with the wall for 0.040 s. What is the acceleration of the ball ?

### Lakhmir Singh solutions for Science Class 9 Physics Chapter 1 Motion Very Short Answers, Short Answers, Long Answers, MCQ, Hots Questions [Pages 39 - 44]

Very Short Answers | Q 1.1 | Page 39

What remains constant in uniform circular motion ?

Very Short Answers | Q 1.2 | Page 39

What changes continuously in uniform circular motion ? ‘

Very Short Answers | Q 2 | Page 39

State whether the following statement is true or false :
Earth moves round the sun with uniform velocity.

Very Short Answers | Q 3 | Page 39

A body goes round the sun with constant speed in a circular orbit. Is the motion uniform or accelerated ?

Very Short Answers | Q 4 | Page 39

What conclusion can you draw about the velocity of a body from the displacement-time graph shown below : Very Short Answers | Q 5 | Page 39

Name the quantity which is measured by the area occupied under the velocity-time graph.

Very Short Answers | Q 6 | Page 39

What does the slope of a speed-time graph indicate ?

Very Short Answers | Q 7 | Page 39

What does the slope of a distance-time graph indicate ?

Very Short Answers | Q 8 | Page 39

Give one example of a motion where an object does not change its speed but its direction of motion changes continuously.

Very Short Answers | Q 9 | Page 39

Name the type of motion in which a body has a constant speed but not constant velocity.

Very Short Answers | Q 10 | Page 39

What can you say about the motion of a body if its speed-time graph is a straight line parallel to the time axis ?

Very Short Answers | Q 11 | Page 40

What conclusion can you draw about the speed of a body from the following distance-time graph ? Very Short Answers | Q 12 | Page 40

What can you say about the motion of a body whose distance-time graph is a straight line parallel to the time axis ?

Very Short Answers | Q 13 | Page 40

What conclusion can you draw about the acceleration of a body from the speed-time graph shown below . Very Short Answers | Q 14 | Page 40

A satellite goes round the earth in a circular orbit with constant speed. Is the motion uniform or accelerated ?  Very Short Answers | Q 15 | Page 40

What type of motion is represented by the tip of the ‘seconds’ hand’ of a watch ? Is it uniform or accelerated ?

Very Short Answers | Q 16.1 | Page 40

Fill in the following blank with suitable word :

If a body moves with uniform velocity, its acceleration is  ..............

Very Short Answers | Q 16.2 | Page 40

Fill in the following blank with suitable word :

The slope of a distance-time graph indicates ………………….. of a moving body.

Very Short Answers | Q 16.3 | Page 40

Fill in the following blank with suitable word :

The slope of a speed-time graph of a moving body gives its………………………..

Very Short Answers | Q 16.4 | Page 40

Fill in the following blank with suitable word :

In a speed-time graph, the area enclosed by the speed-time curve and the time axis gives the…………….. by the body.

Very Short Answers | Q 16.5 | Page 40

Fill in the following blank with suitable word :

It is possible for something to accelerate but not change its speed if it moves in a………………………..

Short Answers | Q 17 | Page 41

Is the uniform circular motion accelerated ? Give reasons for your answer

Short Answers | Q 18 | Page 41

Write the formula to calculate the speed of a body moving along a circular path. Give the meaning of each symbol which occurs in it.

Short Answers | Q 19 | Page 41

Explain why, the motion of a body which is moving with constant speed in a circular path is said to be accelerated.

Short Answers | Q 20 | Page 41

What is the difference between uniform linear motion and uniform circular motion ? Explain with examples.

Short Answers | Q 21 | Page 41

State an important characteristic of uniform circular motion. Name the force which brings about uniform circular motion.

Short Answers | Q 22 | Page 41

Find the initial velocity of a car which is stopped in 10 seconds by applying brakes. The retardation due to brakes is 2.5 m/s2.

Short Answers | Q 23 | Page 41

Describe the motion of a body which is accelerating at a constant rate of 10 m s2. If the body starts from rest, how much distance will it cover in 2 s ?

Short Answers | Q 24 | Page 41

A motorcycle moving with a speed of 5 m/s is subjected to an acceleration of 0.2 m/s2. Calculate the speed of the motorcycle after 10 seconds, and the distance travelled in this time.

Short Answers | Q 25 | Page 41

A bus running at a speed of 18 km/h is stopped in 2.5 seconds by applying brakes. Calculate the retardation produced.

Short Answers | Q 26 | Page 41

A train starting from rest moves with a uniform acceleration of 0.2 m/s2 for 5 minutes. Calculate the speed acquired and the distance travelled in this time.

Short Answers | Q 27.1 | Page 41

Name the two quantities, the slope of whose graph give speed .

Short Answers | Q 27.2 | Page 41

Name the two quantities, the slope of whose graph give acceleration.

Short Answers | Q 28 | Page 41

A cheetah starts from, rest, and accelerates at 2 m/s2 for 10 seconds. Calculate :
(a) the final velocity
(b) the distance travelled.

Short Answers | Q 29 | Page 41

A train travelling at 20 m s-1 accelerates at 0.5 m s-2 for 30 s. How far will it travel in this time ?

Short Answers | Q 30 | Page 41

A cyclist is travelling at 15 m s-1. She applies brakes so that she does not collide with a wall 18 m away. What deceleration must she have ?

Short Answers | Q 31 | Page 41

Draw a velocity-time graph to show the following motion :
A car accelerates uniformly from rest for 5 s ; then it travels at a steady’ velocity for 5 s.

Short Answers | Q 32.1 | Page 41

The velocity-time graph for part of a train journey is a horizontal straight line. What does this tell you about the trains velocity.

Short Answers | Q 32.2 | Page 41

The velocity-time graph for part of a train journey is a horizontal straight line. What does this tell you about its acceleration ?

Long Answers | Q 33.1 | Page 41

Explain the meaning of the following equation of motion :v = u + at, where symbols have their usual meanings.

Long Answers | Q 33.2 | Page 41

A body starting from rest travels with uniform acceleration. If it travels 100 m in 5 s, what is the value of acceleration ?

Long Answers | Q 34.1 | Page 41

Derive the formula : v = u + at, where the symbols have usual meanings.

Long Answers | Q 34.2 | Page 41

A bus was moving with a speed of 54 km/h. On applying brakes it stopped in 8 seconds. Calculate the acceleration.

Long Answers | Q 35.1 | Page 41

Derive the formula s= ut+1/2at^2 , where the symbols have usual meanings.

Long Answers | Q 35.2 | Page 41

A train starting from stationary position and moving with uniform acceleration attains a speed of 36 km per hour in 10 minutes. Find its acceleration.

Long Answers | Q 36.1 | Page 41

Write the three equation of uniformly accelerated motion. Give the meaning of  symbol which occurs in them.

Long Answers | Q 36.2 | Page 41

A car acquire a velocity of 72 km per hour in 10 second starting from rest. Find

(1) the acceleration,
(2) the average velocity, and
(3) the distance travelled in this time.

Long Answers | Q 37.1 | Page 41

What is meant by uniform circular motion? Give two examples of uniform circular motion.

Long Answers | Q 37.2 | Page 41

The tip of seconds’ hand of a dock takes 60 seconds to move once on the circular dial of the clock. If the radius of the dial of the clock be 10.5 cm, calculate the speed of the tip of the seconds’ hand of the clock. ("Given"  π= 22/7).

Long Answers | Q 38 | Page 42

Show by means of graphical method that: v = u + at, where the symbols have their usual meanings.

Long Answers | Q 39 | Page 42

Show by using the graphical method that: s=ut+1/2at^2 where the symbols have their usual meanings.

Long Answers | Q 40 | Page 42

Derive the following equation of motion by the graphical method : v2 = u2 + 2as, where the symbols have their usual meanings.

MCQ | Q 41 | Page 42

A bus increases its speed from 36 km/h to 72 km/h in 10 seconds. Its acceleration is :

• 5 m/s2

• 2 m/s2

• 3.6 m/s2

• 1 m/s2

MCQ | Q 42 | Page 42

A bus moving along a straight line at 20 m/s undergoes an acceleration of 4 m/s2. After 2 seconds, its speed will be:

•  8 m/s

• 12 m/s

• 16 m/s

• 28 m/s

MCQ | Q 43 | Page 42

The slope of a speed-time graph gives:

• distance travelled

• velocity

• acceleration

• displacement

MCQ | Q 44 | Page 42

The area under a speed-time graph represents a physical quantity which has the unit of :

• m

• m2

• m s−1

• m s−2

MCQ | Q 45 | Page 42

If the displacement of an object is proportional to the square of time, then the object is moving with :

• uniform velocity

• uniform acceleration

• increasing acceleration

• decreasing acceleration

MCQ | Q 46 | Page 42

Four cars A, B, C and D are moving on a levelled, straight road. Their distance-time graphs are shown in the given figure. Which of the following is the correct statement regarding the motion of these cars? •  car A is faster than car D

• car B is the slowest

• car D is faster than the car C

• car C is the slowest

MCQ | Q 47 | Page 42

A car of mass 1000 kg is moving with a velocity of 10 m s−1. If the velocity-time graph for this car is a horizontal line parallel to the time axis, then the velocity of car at the end of 25 s will be :

• 25 m s−1

• 40 m s−1

• 10 m s−1

• 250 m s−1

MCQ | Q 48 | Page 42

A motorcycle is being driven at a speed of 20 m/s when brakes are applied to bring it to rest in five seconds. The deceleration produced in this case will be :

• + 4 m/s2

• − 4 m/s2

• + 0.25 m/s2

• −0.25 m/s2

MCQ | Q 49 | Page 42

A sprinter is running along the circumference of a big sports stadium with constant speed. Which of the following do you think is changing in this case?

• magnitude of acceleration being produced

• distance covered by the sprinter per second

• direction in which the sprinter is running

• centripetal force acting on the sprinter

MCQ | Q 50 | Page 42

In the speed-time graph for a moving object shown here, the part which indicates uniform deceleration of the object is : • ST

• QR

• RS

• PQ

MCQ | Q 51 | Page 42

A student draws a distance-time graph for a moving scooter and finds that a section of the graph is horizontal line parallel to the time axis. Which of the following conclusion is correct about this section of the graph?

• the scooter has uniform by scooter is the maximum in this section

• the distance travelled by scooter is the maximum in this section

• the distance travelled by scooter is the minimum in this section

•  the distance travelled by the scooter is zero in this section

MCQ | Q 52 | Page 43

Which one of the following is most likely not a case of uniform circular motion?

• motion of the earth around the sun

• motion of a toy train on a circular track

• motion of a racing car on a circular track

• motion of hours' hand on the dial of a clock

Hots Questions | Q 53 | Page 43

The graph given alongside shows the positions of a body at different times. Calculate the speed of the body as it moves from :
(1) A to B,
(2) B to C, and
(3) C to D. Hots Questions | Q 54.1 | Page 43

What can you say about the motion of a body if:
its displacement-time graph is a straight line ?

Hots Questions | Q 54.2 | Page 43

What can you say about the motion of a body if:
its velocity-time graph is a straight line ?

Hots Questions | Q 55 | Page 43

A body with an initial velocity x moves with a uniform acceleration y. Plot its velocity-time graph.

Hots Questions | Q 56 | Page 43

Given alongside is the velocity-time graph for a moving body :
Find :
(i) Velocity of the body at point C.
(ii) Acceleration acting on the body between A and B.
(iii) Acceleration acting on the body between B and C. Hots Questions | Q 57 | Page 43

A body is moving uniformly in a straight line with a velocity of 5 m/s. Find graphically the distance covered by it in 5 seconds.

Hots Questions | Q 58 | Page 43

The speed-time graph of an ascending passenger lift is given alongside. What is the acceleration of the lift:
(1) during the first two seconds ?
(2) between second and tenth second ?
(3) during the last two seconds ?

Hots Questions | Q 59 | Page 43

A car is moving on a straight road with uniform acceleration. The speed of the car varies with time as follows :
Time (s)              :     0          2         4          6       8         10
Speed (m/s)       :     4          8       12        16     20         24
Draw the speed-time graph by choosing a convenient scale. From this graph : (1) Calculate the acceleration of the car.
(2) Calculate the distance travelled by the car in 10 seconds.

Hots Questions | Q 60 | Page 43

The graph given alongside shows how the speed of a car changes with time: (i) What is the initial speed of the car ?
(ii) What is the maximum speed attained by the car ?
(iii) Which part of the graph shows zero acceleration ?
(iv) Which part of the graph shows varying retardation ?
(v) Find the distance travelled in first 8 hours.

Hots Questions | Q 61 | Page 43

Three speed-time graphs are given below : Which graph represents the case of:
(i) a cricket ball thrown vertically upwards and returning to the hands of the thrower ?
(ii) a trolley decelerating to a constant speed and then accelerating uniformly ?

Hots Questions | Q 62 | Page 44

Study the speed-time graph of a car given alongside and answer the following questions: (i) What type of motion is represented by OA ?
(ii) What type of motion is represented by AB ?
(iii) What type of motion is represented by BC ?
(iv) What is the acceleration of car from O to A ?
(v)What is the acceleration of car from A to B ?
(vi) What is the retardation of car from B to C ?

Hots Questions | Q 63.1 | Page 44

What type of motion is represented by the following graph ? Hots Questions | Q 63.2 | Page 44

What type of motion is represented by the following graph ? Hots Questions | Q 63.3 | Page 44

What type of motion is represented by the following graph ? Hots Questions | Q 63.4 | Page 44

What type of motion is represented by the following graph ? Hots Questions | Q 64 | Page 44

A car is travelling along the road at 8 ms-1. It accelerates at 1 ms-2 for a distance of 18 m. How fast is it then travelling ?

Hots Questions | Q 65 | Page 44

A car is travelling at 20 m/s along a road. A child runs out into the road 50 m ahead and the car driver steps on the brake pedal. What must the car’s deceleration be if the car is to stop just before it reaches the child ?

## Chapter 1: Motion ## Lakhmir Singh solutions for Science Class 9 Physics chapter 1 - Motion

Lakhmir Singh solutions for Science Class 9 Physics chapter 1 (Motion) include all questions with solution and detail explanation. This will clear students doubts about any question and improve application skills while preparing for board exams. The detailed, step-by-step solutions will help you understand the concepts better and clear your confusions, if any. Shaalaa.com has the CBSE Science Class 9 Physics solutions in a manner that help students grasp basic concepts better and faster.

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Concepts covered in Science Class 9 Physics chapter 1 Motion are Motion (Introduction), Distance and Displacement, Describing Motion, Motion Along a Straight Line, Uniform Motion and Nonuniform Motion, Measuring the Rate of Motion - Speed with Direction, Rate of Change of Velocity, Distance-time Graphs, Velocity-time Graphs, Derivation of Equations of Motion by Graphical Method, Equation for Velocity-time Relation, Equation for Position-time Relation, Equation for Position-velocity Relation, Uniform Circular Motion, Motion (Numerical), Graphical Representation of Motion, Equations of Motion by Graphical Method.

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