# Motion Class 9 NCERT solutions

## In this pdf file you can see answers of following Questions

### NCERT Solutions Intext Questions Page no.100

Question 1. An object has moved through a distance. Can it have zero displacement? If yes, support your answer with an example.

Question 2. A farmer moves along the boundary of a square field of side 10 m in 40 s. What will be the magnitude of displacement of the farmer at the end of 2 minutes 20 seconds?

Question 3. Which of the following is true for displacement?
(a) It cannot be zero.
(b) Its magnitude is greater than the distance travelled by the object.

### NCERT Solutions Intext Questions Page no.102

Question 1. Distinguish between speed and velocity.

Question 2. Under what condition(s) is the magnitude of average velocity of an object equal to its average speed?

Question 3. What does the odometer of an automobile measure?

Question 4. What does the path of an object look like when it is in uniform motion?

Question 5. During an experiment, a signal from a spaceship reached the ground station in five minutes. What was the distance of the spaceship from the ground station? The signal travels at the speed of

### NCERT Solutions Intext Questions Page no.103

Question 1. When will you say a body is in
(i) uniform acceleration?
(ii) nonuniform acceleration?

Question 2. A bus decreases its speed from 80 km h–1 to 60 km h–1 in 5 s. Find the acceleration of the bus.

Question 3. A train starting from a railway station and moving with uniform acceleration attains a speed 40 km h–1 in 10 minutes. Find its acceleration.

#### NCERT Solutions Intext Questions Page no.107

Question 1. What is the nature of the distance-time graphs for uniform and non-uniform motion of an object?

Question 2. What can you say about the motion of an object whose distance-time graph is a straight line parallel to the time axis?

Question 3. What can you say about the motion of an object if its speedtime graph is a straight line parallel to the time axis?

Question 4. What is the quantity which is measured by the area occupied below the velocity-time graph?

#### NCERT Solutions Intext Questions Page no.109

Question 1. A bus starting from rest moves with a uniform acceleration of 0.1 m s-2 for 2 minutes. Find
(a) The speed acquired,
(b) The distance travelled

#### NCERT Solutions Intext Questions Page no.110

Question 2. A train is travelling at a speed of 90 km h–1. Brakes are applied so as to produce a uniform acceleration of – 0.5 m s-2. Find how far the train will go before it is brought to rest.

Question 3. A trolley, while going down an inclined plane, has an acceleration of 2 cm s-2. What will be its velocity 3 s after the start?

Question 4. A racing car has a uniform acceleration of 4 m s-2. What distance will it cover in 10 s after start?

Question 5. A stone is thrown in a vertically upward direction with a velocity of 5 m s-1. If the acceleration of the stone during its motion is 10 m s–2 in the downward direction, what will be the height attained by the stone and how much time will it take to reach there?

#### NCERT Solutions Exercises Questions

Question 1. An athlete completes one round of a circular track of diameter 200 m in 40 s. What will be the distance covered and the displacement at the end of 2 minutes 20 s?

Question 2. Joseph jogs from one end A to the other end B of a straight 300 m road in 2 minutes 50 seconds and then turns around and jogs 100 m back to point C in another 1 minute. What are Joseph’s average speeds and velocities in jogging
(a) from A to B and (b) from A to C?

Question 3. Abdul, while driving to school, computes the average speed for his trip to be 20 km h–1. On his return trip along the same route, there is less traffic and the average speed is 40 km h–1. What is the average speed for Abdul’s trip?

Question 4. A motorboat starting from rest on a lake accelerates in a straight line at a constant rate of 3.0 m s–2 for 8.0 s. How far does the boat travel during this time?

Question 5. A driver of a car travelling at 52 km h–1 applies the brakes and accelerates uniformly in the opposite direction. The car stops in 5 s. Another driver going at 3 km h–1 in another car applies his brakes slowly and stops in 10 s. On the same graph paper, plot the speed versus time graphs for the two cars. Which of the two cars travelled farther after the brakes were applied?

Question 6. Fig 8.11 shows the distance-time graph of three objects A,B and C. Study the graph and answer the following questions:

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