Multiple Choice Questions (MCQs)
1. If the change in velocity is the same in equal intervals of time, what is the acceleration called?
a) Variable acceleration b) Uniform acceleration c) Zero acceleration d) Average acceleration
2. The gradient of the speed-time graph is equal to:
a) speed b) velocity c) acceleration d) distance covered
3. What is an example of Translatory motion?
a) Motion of a swing b) Motion of a fan c) Motion of a train d) Motion of a top
4. If an object continuously changes its position relative to its surroundings, what is it called?
a) State of motion b) State of rest c) Oscillation d) Static
5. If the speed or direction or both of velocity are changing, what is such velocity called?
a) Uniform velocity b) Variable or non-uniform velocity c) Constant velocity d) Zero velocity
6. The direction of velocity will be the same as the direction of what?
a) Speed b) Distance c) Displacement d) Acceleration
7. What type of motion is a freely falling body an example of?
a) Non-uniform acceleration b) Circular motion c) Linear motion d) Rotatory motion
8. What is the total displacement of a body in unit time (one second) called?
a) Random motion b) Velocity c) Acceleration d) Distance
9. What kind of quantity is speed?
a) Speed b) Vector quantity c) Scalar quantity d) Derived vector
10. What is necessary to completely describe a scalar quantity?
a) Numerical value and direction b) Only numerical value c) Only direction d) Unit and direction
11. Which of the following is a scalar quantity?
a) Distance b) Displacement c) Velocity d) Weight
12. The gradient of the distance-time graph is equal to:
a) speed b) distance covered c) velocity d) acceleration
13. How can scalar quantities be added?
a) By special methods b) Like ordinary numbers c) Only by multiplication d) Only by division
14. A body accelerates from rest to a velocity of $144\text{ km h}^{-1}$ in 20 seconds. Then the distance covered by it is:
a) 100 m b) 400 m c) 1400 m d) 1440 m
15. If an object moves in a circle, what is it called?
a) Linear motion b) Random motion c) Rotatory motion d) Circular motion
16. What kind of quantity is displacement?
a) Scalar quantity b) Vector quantity c) Numerical quantity d) Invariable quantity
17. Kinematics is the study of what?
a) Forces and their effects b) Motion of bodies without reference to force c) Force and power d) Energy and work
18. How many types of Mechanics are there?
a) One b) Two c) Three d) Four
19. What is the formula for speed?
a) v = S \times t
b) v = S / t
c) v = t / S
d) v = S + t
20. If an object repeatedly moves back and forth from its rest position, what is such motion called?
a) Rotatory motion b) Translatory motion c) Circular motion d) Vibratory motion
21. What is distance actually?
a) The shortest distance between initial and final positions b) The length of the path covered c) Change in position d) Path covered with direction
22. What is the speed of a vehicle at any moment shown by its speedometer called?
a) Average speed b) Instantaneous speed c) Uniform speed d) Non-uniform speed
23. What type of motion is the motion of an electric machine or a washing machine dryer?
a) Translatory motion b) Vibratory motion c) Linear motion d) Rotatory motion
24. If velocity is increasing, what will the acceleration be?
a) Negative b) Zero c) Positive d) Invariable
25. When an object does not change its position relative to its surroundings, what state is it in?
a) At rest b) In motion c) In vibratory state d) In rotatory state
26. What else is negative acceleration called?
a) Retardation b) Acceleration c) Velocity d) Speed
27. What kind of quantity is velocity?
a) Scalar quantity b) Vector quantity c) Numerical quantity d) Constant quantity
28. What is the Head-to-Tail Rule used for?
a) For adding scalar quantities b) For adding vectors c) For finding distance d) For finding speed
29. If the speed and direction of a moving object do not change, what is its velocity called?
a) Uniform b) Non-uniform c) Variable d) Instantaneous
30. How are vectors represented graphically?
a) By a round circle b) By a straight line with an arrow at one end c) By a point d) By a curved line
31. A ball is dropped from the top of a tower. The distance covered by it in the first second is:
a) 5 m b) 10 m c) 50 m d) 100 m
32. What are the two thick perpendicular lines used to draw a graph called?
a) Origin b) Axes c) Coordinates d) Directions
33. What is the rate of change of an object’s velocity with time called?
a) Speed b) Velocity c) Acceleration d) Displacement
34. On what paper are graphs usually drawn?
a) Plain paper b) Lined paper c) Graph paper d) Colored paper
35. Which of the following is a vector quantity?
a) Acceleration b) Speed c) Time d) Energy
36. The area under the speed-time graph is numerically equal to:
a) velocity b) uniform velocity c) acceleration d) distance covered
37. What is used to show the direction of a vector?
a) Only horizontal line b) Only vertical line c) Two mutually perpendicular lines d) Any line
38. What is the formula for average speed?
a) Average speed = (Total distance covered) / (Total time) b) Average speed = (Total time) / (Total distance covered) c) Average speed = Distance x Time d) Average speed = Displacement / Time
39. If a body does not change its position with respect to some fixed point, then it will be in a state of:
a) rest b) motion c) uniform motion d) variable motion
40. The direction of acceleration will be in the direction of what?
a) Speed b) Change in velocity c) Distance d) Time
41. What is necessary to completely describe a vector quantity?
a) Only numerical value b) Only direction c) Both numerical value and direction d) Mass
42. What is the origin usually represented by?
a) X b) Y c) O d) A
43. What type of motion is the flight of a honeybee called?
a) Circular motion b) Linear motion c) Random motion d) Vibratory motion
44. A body is moving with constant acceleration starting from rest. It covers a distance S in 4 seconds. How much time does it take to cover one-fourth of this distance?
a) 1 s b) 2 s c) 4 s d) 16 s
45. What does a graph represent?
a) Only one physical quantity b) The relationship between two physical quantities in pictorial form c) Time d) Distance
Short Answer Questions
- For a complete trip, average velocity was calculated. Its value came out to be positive. Is it possible that its instantaneous velocity at any time during the trip had the negative value? Give justification of your answer.
- What are distance-time graph and speed-time graph?
- Is it possible for a body to have acceleration? When moving with: (i) constant velocity (ii) constant speed
- Define Rotatory motion and give an example.
- What is meant by Instantaneous Speed?
- Write the formula for average acceleration.
- What special methods are required to add vectors?
- What is the SI unit of velocity?
- What is Translatory motion? Give an example.
- What is the Head-to-Tail Rule? Explain.
- When a bullet is fired, its velocity with which it leaves the barrel is called the muzzle velocity of the gun. The muzzle velocity of one gun with a longer barrel is lesser than that of another gun with a shorter barrel. In which gun is the acceleration of the bullet larger? Explain your answer.
- Define Resultant Vector.
- Define the state of Rest and give an example.
- What is meant by Circular motion? Give an example.
- What is meant by Graphical Analysis of Motion?
- Differentiate between Uniform and Non-Uniform Velocity.
- The vector quantities are sometimes written in scalar notation (not bold face). How is the direction indicated?
- Name the types of motion.
- What is the SI unit of speed?
- Why are mass, distance, speed, time, energy, and temperature scalar quantities?
- Give 5 examples each for scalar and vector quantities.
- How does a graph represent the relationship between two physical quantities?
- Is it possible that the velocity of an object is zero at an instant of time, but its acceleration is not zero? If yes, give an example of such a case.
- What is meant by a vector quantity? Give examples.
- What is the role of axes in drawing a graph?
- Define Kinematics.
- What is the difference between Dynamics and Kinematics?
- Define Random motion and give an example.
- Explain the difference between Uniform and Non-Uniform Acceleration.
- What is the difference between Distance and Displacement?
- With respect to which angle is the direction of a vector usually given?
- What is the SI unit of acceleration?
- A body is moving with uniform speed. Will its velocity be uniform? Give reason.
- Why are change in position, force, weight, velocity, and acceleration vector quantities?
- Define scalar and vector quantities.
- Distance and displacement may or may not be equal in magnitude. Explain this statement.
- Define Speed and write its formula.
- How does the state of rest and motion depend on the observer? Explain with an example.
- What is meant by a scalar quantity? Give examples.
- What is meant by Linear motion?
- How is a vector represented graphically?
- Define Velocity and write its formula.
- What is Vibratory motion? Give an example.
- What is meant by Deceleration or Retardation?
- Define Average Speed and write its formula.
- Falling objects near the Earth have the same constant acceleration. Does this imply that a heavier object will fall faster than a lighter object?
- How are vectors represented in common textbooks and when written by hand?
- What is the difference between positive and negative acceleration?
- Why does a paratrooper move downwards with uniform velocity?
- Define the state of Motion and give an example.
- State head-to-tail rule for addition of vectors.
- Define Acceleration.
Long Questions
- Derive the three equations of motion using algebraic methods.
- Differentiate between distance and displacement with an example.
- Draw the representative lines of the following vectors: (a) A velocity of 400\text{ m s}^{-1} making an angle of 60^{\circ} with the x-axis. (b) A force of 50 N making an angle of 120^{\circ} with x-axis.
- A car is moving with an average speed of 72 km^-1. How much time will it take to cover a distance of 360 km?
- An eagle dives to the ground along a 300 m path with an average speed of 60\text{ m s}^{-1}. How long does it take to cover this distance?
- What do gradients of distance-time graph and speed-time graph represent? Explain it by drawing diagrams.
- Differentiate between: (i) rest and motion (ii) speed and velocity.
- A stone is dropped from a height of 45 m. How long will it take to reach the ground? What will be its velocity just before hitting the ground?
- How equations of motion can be applied to the bodies moving under the action of gravity?
- Prove that the area under speed-time graph is equal to the distance covered by an object.
- Explain the difference between distance and displacement.
- How a vector can be represented graphically? Explain.
- A cricket ball is hit so that it travels straight up in the air. An observer notes that it took 3 seconds to reach the highest point. What was the initial velocity of the ball? If the ball was hit 1 m above the ground, how high did it rise from the ground?
- Describe different types of motion. Also give examples.
- A car passes a green traffic signal while moving with a velocity of 5\text{ ms}^{-1}. It then accelerates to 1.5\text{ ms}^{-2}. What is the velocity of car after 5 seconds?
- Draw the velocity vector \mathbf{v}; a velocity of 300\text{ ms}^{-1} at an angle of 60^{\circ} to the east of north.
- A plane starts running from rest on a run-way as shown in the figure below. It accelerates down the run-way and after 20 seconds attains a velocity of 252\text{ km h}^{-1}. Determine the average acceleration of the plane.
- Define vector and scalar quantities with at least four examples each.
- An eagle dives along a 300 m path with an average speed of 60\text{ m/s}. How long does it take to cover this distance?
- A wagon is moving on the road with a velocity of 54\text{ km h}^{-1}. Brakes are applied suddenly. The wagon covers a distance of 25 m before stopping. Determine the acceleration of the wagon.
- Discuss the graphical representation of motion with examples.
- A ball is thrown vertically upward with a speed of 30\text{ m/s}. Find the maximum height it will reach.
- Draw a force vector \mathbf{F} having magnitude of 350 N and acting at an angle of 60^{\circ} with x-axis.
- Explain the concept of free fall and derive the equations of motion for a freely falling body.
- An iron bob is dropped from the top of a tower. It reaches the ground in 4 seconds. Find: (a) the height of the tower (b) the velocity of the ball as it strikes the ground.
- A truck starts from rest. It reaches a velocity of 90\text{ km h}^{-1} in 50 seconds. Find its average acceleration.
- Explain the types of motion with diagrams.
- An arrow is thrown vertically upward with the help of a bow. The velocity of the arrow when it leaves the bow is $30\text{ m s}^{-1}$. Determine time to reach the highest point? Also, find the maximum height attained by the arrow.
- A motorcycle initially travelling at 18\text{ km h}^{-1} accelerates at constant rate of 2\text{ ms}^{-2}. How far will the motorcycle go in 10 seconds?
- A car travels 10 km with an average velocity of 20\text{ m s}^{-1}. Then it travels in the same direction through a diversion at an average velocity of 4\text{ m s}^{-1} for the next 0.8 km. Determine the average velocity of the car for the total journey.
- A plane accelerates from rest to a velocity of 252\text{ km/h} in 20 seconds. Find its acceleration.
- A ball is dropped from the top of a tower. The ball reaches the ground in 5 seconds. Find the height of the tower and the velocity of the ball with which it strikes the ground.
- A car starts from rest and accelerates at 2\text{ m/s}^{2} for 10 s. Find its final velocity.
Physics 9th New Answer Key
MCQs Answer Key
- Uniform acceleration
- acceleration
- Motion of a train
- State of motion
- Variable or non-uniform velocity
- Displacement
- Linear motion
- Velocity
- Scalar quantity
- Only numerical value
- Distance
- speed
- Like ordinary numbers
- 400 m
- Circular motion
- Vector quantity
- Motion of bodies without reference to force
- Two
- v=S/t
- Vibratory motion
- The length of the path covered
- Instantaneous speed
- Rotatory motion
- Positive
- At rest
- Retardation
- Vector quantity
- For adding vectors
- Uniform
- By a straight line with an arrow at one end
- 5 m
- Axes
- Acceleration
- Graph paper
- Acceleration
- distance covered
- Two mutually perpendicular lines
- Average speed = (Total distance covered) / (Total time)
- rest
- Change in velocity
- Both numerical value and direction
- O
- Random motion
- 2 s
- The relationship between two physical quantities in pictorial form