Motion Class 9 Extra Questions Physics | Motion Numericals

 Motion Class 9 Physics

Source - S Chand

Multiple Choice Questions (MCQs)
42. A particle is moving in a circular path of radius r. The displacement after half a circle would be :
(a) 0 (b) rtr (c) 2r (4) 2itr
43. The numerical ratio of displacement to distance for a moving object is :
(a) always less than 1 (b) equal to 1 or more than 1 (c) always more than 1 (d) equal to 1 or less than 1
44. 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 :
(a) at rest (1) moving with no acceleration (c) in accelerated motion  (d) moving with uniform velocity
 45. In which of the following cases of motion, the distance moved and the magnitude of displacement are equal?
(a) if the car is moving on straight road (b) if the car is moving on circular road (c) if the pendulum is moving to and fro   (d) if a planet is moving around the sun
 
46. The speed of a moving object is determined to be 0.06 m/s. This speed is equal to :
(a) 2.16 km/h (b) 1.08 km/h (c) 0.216 km/h (h) 0.0216 km/h
 
 
47. A freely falling object travels 4.9 m in 1st second, 14.7 m in 2nd 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 :
(a) uniform motion
(b) uniform acceleration
(c) no acceleration
(d) uniform velocity
 
48. When a car runs on a circular track with a uniform speed, its velocity is said to be changing. This is because:
(a) the car has a uniform acceleration
(b) the direction of car varies continuously
(c) the car travels unequal distances in equal time intervals
(d) the car travels equal distances in unequal time intervals
 
49. Which of the following statement is correct regarding velocity and speed of a moving body?
 (a) velocity of a moving body is always higher than its speed
(b) speed of a moving body is always higher than its velocity
(c) speed of a moving body is its velocity in a given direction
(d) velocity of a moving body is its speed in a given direction
 
50. Which of the following can sometimes be 'zero' for a moving body?
(i) average velocity (ii) distance travelled (iii) average speed (iv) displacement
(a) only (i)   (b) (i) and (ii) (c) (i) and (iv) (d) only (iv)
51. 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 :
(a) + 2 in/s2 (b) — 2 m/s2 (c) — 0.5 in/s2 (d) + 0.5 m/s2
 
52. Which of the following could not be a unit of speed?
(a) km/h (b) s/m (c) m/s (d) mm s-1
 
53. One of the following is not a vector quantity. This one is:
(a) displacement (b) speed (c) acceleration (d) velocity
 
54. Which of the following could not be a unit of acceleration?
(a) km/s2 (b) cm s-2 (c) km/s  (d) m/s2
Short Answer Type Questions
1. Is displacement a scalar quantity?
2. State whether distance is a scalar or a vector quantity.
3. Change the speed of 6 m/s into km/h.
4. What name is given to the speed in a specified direction?
5. Give two examples of bodies having non-uniform motion.
 6. Name the physical quantity obtained by dividing 'Distance travelled' by 'Time taken' to travel that distance.
7. What do the following measure in a car? (a) Speedometer (b) Odometer
 
8. Name the physical quantity which gives us an idea of how slow or fast a body is moving.
9. Under what conditions can a body travel a certain distance and yet its resultant displacement be zero ?
10. In addition to speed, what else should we know to predict the position of a moving body ?
11. When is a body said to have uniform velocity ?
12. Under which condition is the magnitude of average velocity equal to average speed ?
13. Which of the two can be zero under certain conditions : average speed of a moving body or average velocity of a moving body ?
14. Give one example of a situation in which a body has a certain average speed but its average velocity is zero.
15. What is the acceleration of a body moving with uniform velocity ?
16. What is the other name of negative acceleration ?
17. Name the physical quantity whose SI unit is : (a) m/s (13) m/s2
18. What type of motion is exhibited by a freely falling body ?
19. What is the SI unit of retardation ?
20. Fill in the following blanks with suitable words :
(a) Displacement is a ……………. quantity whereas distance is a ……………. quantity.
(b) The physical quantity which gives both, the speed and direction of motion of a body is its ………………
(c) A motorcycle has a steady ……………… of 3 m/s2. This means that every …………….. its ……………. Increases by ………………..
(d) Velocity is the rate of change of ………………. It is measured in ……………….
(e) Acceleration is the rate of change of ……………….. It is measured in ……………….
 
 
Short Answer Type Questions
21. What type of motion, uniform or non-uniform, is exhibited by a freely falling body ? Give reason for y answer.
22. State whether speed is a scalar or a vector quantity. Give reason for your choice.
23. Bus X travels a distance of 360 km in 5 hours whereas bus Y travels a distance of 476 km in 7 hours. Why bus travels faster ?
24. Arrange the following speeds in increasing order (keeping the least speed first):
(i) An athlete running with a speed of 10 m/s.
(ii) A bicycle moving with a speed of 200 m/min.
(iii) A scooter moving with a speed of 30 km/h. 25.
(a) Write the formula for acceleration. Give the meaning of each symbol which occurs in it.
 (b) A train starting from Railway Station attains, a speed of 21 rn/s in one minute. Find its acceleration.
 
26. (a) What term is used to denote the change of velocity with time ?
(b) Give one word which means the same as 'moving with a negative acceleration'.
(c) The displacement of a moving object in a given interval of time is zero. Would the distance travelled the object also be zero ? Give reason for your answer.
27. A snail covers a distance of 100 metres in 50 hours. Calculate the average speed of snail in km/h.
 
28. A tortoise moves a distance of 100 metres in 15 minutes. What is the average speed of tortoise in km/h ?
29. If a sprinter runs a distance of 100 metres in 9.83 seconds, calculate his average speed in km/h.
30. A motorcyclist drives from place A to B with a uniform speed of 30 km h-1 and returns from place 13 to A with a uniform speed of 20 km h-1. Find his average speed.
31. 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 ?
32. 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' ?
33. 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 Answer Type Questions
34. (a) What is the difference between 'distance travelled' by a body and its 'displacement' ? Explain with the help of a diagram.
(b) 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.
35. Define motion. What do you understand by the terms 'uniform motion' and 'non-uniform motion' ? Explain with examples.
36. (a) Define speed. What is the SI unit of speed ?
(b) What is meant by
(i) average speed, and (ii) uniform speed ?
37. (a) Define velocity. What is the SI unit of velocity ?
(b) What is the difference between speed and velocity ?
(c) Convert a speed of 54 km/h into m/s.
38. (a) What is meant by the term 'acceleration' ? State the SI unit of acceleration.
(b) Define the term 'uniform acceleration'. Give one example of a uniformly accelerated motion.
39. The distance between Delhi and Agra is 200 km. A train travels the first 100 kilihaole t a iosptmley ?of 50 km/h. How fast must the train travel the next 100 km, so as to average 70 km/h for the whole
40. 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.
41. A car is moving along a straight road at a steady speed. It travels 150 m in 5 seconds :
(a) What is its average speed ?
(b) How far does it travel in 1 second ?
(c) How far does it travel in 6 seconds ?
(d) How long does it take to travel 240 m ?