NCERT Book Class 9 Science Motion Questions

MOTION

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

(a) Zero

(b) π r

(c) 2 r

(d) 2π r

2. A body is thrown vertically upward with velocity u, the greatest height h to which it will rise is,

(a) u/g     (b) u²/2g     (c) u²/g     (d) u/2g

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

(a) always less than 1

(b) always equal to 1

(c) always more than 1

(d) equal or less than 1

4. If the displacement of an object is proportional to square of time, then the object moves with

(a) uniform velocity

(b) uniform acceleration

(c) increasing acceleration

(d) decreasing acceleration

5. The displacement of a moving object in a given interval of time is zero. Would the distance travelled by the object also be zero? Justify you answer.

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

7. A girl walks along a straight path to drop a letter in the letterbox and comes back to her initial position. Her displacement–time graph is shown in Fig.8.4. Plot a velocity–time graph for the same.

8. A car starts from rest and moves along the x-axis with constant acceleration 5 m s–2 for 8 seconds. If it then continues with constant velocity, what distance will the car cover in 12 seconds since it started from the rest?

9. A motorcyclist drives from A to B with a uniform speed of 30 km h–1 and returns back with a speed of 20 km h–1. Find its average speed.

10. The velocity-time graph (Fig. 8.5) shows the motion of a cyclist. Find (i) its acceleration (ii) its velocity and (iii) the distance covered by the cyclist in 15 seconds.

11. Draw a velocity versus time graph of a stone thrown vertically upwards and then coming downwards after attaining the maximum height.

12. An object is dropped from rest at a height of 150 m and simultaneously another object is dropped from rest at a height 100 m. What is the difference in their heights after 2 s if both the objects drop with same accelerations? How does the difference in heights vary with time?

13. An object starting from rest travels 20 m in first 2 s and 160 m in next 4 s. What will be the velocity after 7 s from the start.

Please refer to attached file for NCERT Class 9 Science Motion Questions