## Motion-Practice Questions for Examinations

### Fill in the Blanks

##### 1. If a car starts at rest and accelerates uniformly, the distance it travels is proportional to the ………. of the time it travels.

##### 2. The speedometer of a car measures its…….. speed.

##### 3. The slope of *x-t *graph gives the………… of motion.

##### 4. Area below v-t graph is a measure of…………………

##### 5. If a car is going northward and the driver jams on its brakes, the direction of its acceleration is………….

##### 6. When an object is going in a circular path at constant speed, the direction of its acceleration is …….

##### 7. A particle moves with a velocity v in a circle of radius r, then its angular velocity is equal to………….. and acts along the…………..

##### 8. The ratio of angular speeds of minute hand and hour hand of watch is

##### 9………… A truck traveling due north at 20 m/s turns left and travels at the same speed. Then the change in velocities……….

##### 10. The magnitude of average velocity ………….equal to the average speed.

### True / False

##### 11. Magnitude of displacement can be equal to or lesser than distance.

##### 12. If particle speed is constant, acceleration of the particle must be zero.

##### 13. A body can have constant velocity and still have varying speed.

##### 14. The movement of the earth about its axis is an example of uniform speed.

##### 15. Unit of speed in S.I. system is cms^{-1}.

##### 16. A body falls freely from a height with uniform acceleration.

##### 17. A particle is known to be at rest at time *t = *0. Its acceleration at *t *= 0 must be zero.

##### 18. In a journey, numerical value of displacement < distance.

##### 19. If a body is moving on a curved path with constant speed, then its acceleration is perpendicular to the direction of motion.

### Match the Columns

##### 20. Match the situation given in column I with the possible curves in column II.

##### 21. Match the items of column I against the items of column II.

### Multiple Choice Questions

#### Questions 22. If a body is moving at constant speed in a circular path, its

##### (a) Velocity is constant and its acceleration is zero

##### (b) Velocity and acceleration are both changing direction only

##### (c) Velocity and acceleration are both increasing

##### (d) Velocity is constant and acceleration is changing direction

#### Question 23. A graph is plotted showing the velocity of a car as a function of time. If the graph is a straight line, it means that

##### (a) the car started at rest

##### (b) acceleration was constant

##### (c) acceleration was increasing

##### (d) velocity was constant

#### Question 24. If a car is traveling north on a straight road and its brakes are applied, it will

##### (a) have no acceleration

##### (b) accelerate to the south

##### (c) accelerate to the north

##### (d) accelerate either east or west

#### Question 25. The acceleration of a car that speeds up from 12 meters per second to 30 meters per second in 15 seconds-

##### (a) 2.4 m/s^{2}

##### (b) 1.2 m/s^{2}

##### (c) 2m/s^{2}

##### (d) 5.2 m/s^{2}

#### Question 26. A car going at 24 meters per second passes a motorcycle at rest. As it passes, the motorcycle starts up, accelerating at 3.2 meters per second squared. If the motorcycle can keep up that acceleration, how long will it take for it to catch the car

##### (a) 12 s

##### (b) 14s

##### (c) 20s

##### (d) 18s

#### Question 27. Mohan takes 20 minutes to cover a distance of 3.2 kilometers due north on a bicycle, his velocity in kilometer/hour-

##### (a) 8.1

##### (b) 9.6

##### (c) 1.2

##### (d) 7.2

#### Question 28. A body moving along a straight line at 20 m/s undergoes an acceleration of-4 m/s^{2}. After two seconds its speed will be

##### (a) -8 m/s

##### (b) 12 m/s

##### (c) 16 m/s

##### (d) 28 m/s

#### Question 29. A particle experiences constant acceleration for 20 seconds after starting from rest. If it travels a distance s_{(} in the first 10 seconds and distance s2 in the next 10 seconds, then

##### (a) s_{2} = s_{1}

##### (b) s_{2} = 2s_{1}

##### (c) s_{2} = 3s_{1}

##### (d) s_{2} = 4s_{1}

#### Question 30 In which of the following cases, the object does not possess an acceleration or retardation when it moves in

##### (a) upward direction with decreasing speed

##### (b) downward direction with increasing speed

##### (c) with constant speed along circular path

##### (d) with constant speed along horizontal direction.

##### ANSWER KEY

**1. Square **

**2. instantaneous **

**3. velocity **

**4. displacement **

**5. South **

**6. centripetal **

**7. v/r, axis of ration **

**8. 12 **

**10. may or may not be **

**11. True **

**12. False **

**13. False **

**14. True **

**15. False **

**1****6. True **

**17. False **

**18. True **

**19. False **

**21. (a) ****(r);(b) ****(p); (c) ****(q); ****(t); (e) ****s**

**22. (b) 23. (b) 24. (b) 25.b) **

**26. (b) 27. (b) 28 (b) 29.(c)**

**30. (d) **