Unit-II: Kinematics
Part A: 30 Multiple Choice Questions (MCQs) with Answers
Which of the following is a scalar quantity?
Displacement
Velocity
Acceleration
Speed
Answer:
d) Speed
A body is said to be at rest if:
It changes its position
It does not change its position with time
It moves at constant speed
Its velocity is increasing
Answer:
b) It does not change its position with time
Which of these graphs represents uniform motion?
Curved position-time graph
St
raight line inclined position-time graph
Horizontal velocity-time graph
Exponential position-time graph
Answer:
b) Straight line inclined position-time graph
Instantaneous speed is:
Total distance/Total time
Very large distance/Very large time
Speed a
t a particular instant
Same as average speed
Answer:
c) Speed at a particular instant
When velocity is constant, acceleration is:
Maximum
Minimum
Zero
Constant
Answer:
c) Zero
Which graph represents constant acceleration?
A
straight line
velocity-time graph
A horizontal position-time graph
A curved velocity-time graph
Exponential position-time graph
Answer:
a) A straight line velocity-time graph
What is the area under a velo
city-time graph?
Speed
Distance/Displacement
Acceleration
Time
Answer:
b) Distance/Displacement
A car moves with uniform acceleration. Its velocity after 5 seconds is 20 m/s. What is its acceleration if it started from rest?
2 m/s²
3 m/s²
4 m/s²
5 m/s²
Answer:
c) 4 m/s²
Which of these is a vector quantity?
Speed
Distance
Displacement
Mass
Answer:
c) Displacement
The vector product of two vectors is called:
Scalar product
Cross product
Dot product
Resultant
Answer:
b) Cross product
In projectile motion, the horizontal component of velocity:
Increases
Decreases
Remai
ns constant
Becomes zero
Answer:
c) Remains constant
Time of flight of a projectile is maximum when angle of projection is:
30°
45°
60°
90°
Answer:
d) 90°
Which one of the following is not a vector?
Velocity
Displacement
Distance
Acceleration
Answ
er:
c) Distance
Which of the following is a unit vector?
A vector with unit magnitude
A vector with unit direction
A vector with unit mass
A vector with unit distance
Answer:
a) A vector with unit magnitude
Dot product of perpendicular vectors is:
1
Maximum
Undefined
Answer:
c) 0
Which of the following is not a valid unit of acceleration?
m/s²
km/h²
m/s
cm/s²
Answer:
c) m/s
The slope of a position-time graph gives:
Acceleration
Velocity
Distance
Time
Answer:
b) Velocity
Acceleration is defined as:
Rate of change of velocity
Rate of change of speed
Displacement per time
None of these
Answer:
a) Rate of change of veloci
ty
Which equation gives displacement in uniformly accelerated motion?
Answer:
a)
( s
= ut + at^2 )
Which of the following quantities remains unchanged in projectile motion?
Vertical velocity
Time of flight
Horizontal velocity
Vertical displacement
Answer:
c) Horizontal velocity
In projectile motion, when is the vertical component of velocity zero?
At the point of projection
At the maximum height
At the point of landing
Never
Answer:
b) At the maximum height
Range is maximum
when angle of projection is:
30°
45°
60°
90°
Answer:
b) 45°
The resultant of two perpendicular vectors of magnitude 3 units and 4 units is:
5 units
7 units
1 unit
12 units
Answer:
a) 5 units
Displacement is zero when:
Path is curved
Path is straight
Initial and final positions are same
Speed is constant
Answer:
c) Initial and final positions are same
Which of the following is dimensionally same as velocity?
Acceleration × Time
Force × Time
Mass × Time
Speed × Time
Answer:
a) Acc
eleration × Time
Relative velocity between two cars moving in same direction with equal speeds is:
Sum of their speeds
Double the speed
Half the speed
Answer:
a) 0
If a vector is multiplied by a scalar, the result is:
A scalar
A vector
Zero
Undef
ined
Answer:
b) A vector
A body is in uniform motion if:
Its acceleration is constant
Its displacement is zero
It covers equal distances in equal intervals of time
It moves in circular path
Answer:
c) It covers equal distances in equal intervals of tim
e
The direction of projectile motion is:
Vertical
Horizontal
Parabolic
Circular
Answer:
c) Parabolic
A particle moves in a circle with constant speed. Its acceleration is:
Zero
Constant in direction
Directed towards center
Directed tangentially
Answer:
c) Directed towards center
Part B: 30 Short Answer Questions (2–3 Marks Each) with Answers
Define scalar and vector quantities with one example each.
Answer:
Scalars have only magnitude (e.g., speed); vectors have both magnitude and direction (e.g., velocity).
What is instantaneous velocity?
Answer:
It is the velocity of a particle at a specific instant of time.
Differentiate between average speed and average v
elocity.
Answer:
Average speed = Total distance / Time; Average velocity = Total displacement / Time.
Give the three equations of motion for uniformly accelerated motion.
Answer:
( v = u +
at )
( s = ut + at^2 )
( v^2 = u^2 + 2as )
What is the slope of a v
elocity-time graph
?
Answer:
Acceleration
Define frame of reference.
Answer:
It is a coordinate system with respect to which the position of an object is measured.
What is the significance of the area under a velocity-time graph?
Answer:
It represents displ
acement of the object.
What is meant by the resolution of a vector?
Answer:
Splitting a vector into its perpendicular components (usually x and y directions).
Give the expression for time of flight in projectile motion.
Answer:
( T
= )
Give the expression
for horizontal range.
Answer:
( R
= )
Give the expression for maximum height.
Answer:
( H
= )
Define relative velocity.
Answer:
It is the velocity of one object with respect to another.
What is the value of dot product of two perpendicular vectors?
Answ
er:
Zero
Define uniform circular motion.
Answer:
Motion of an object in a circular path at constant speed.
What is a unit vector?
Answer:
A vector whose magnitude is one.
State the relation between speed, distance and time.
Answer:
Speed = Distance / Time
What is the difference between displacement and distance?
Answer:
Displacement is vector and depends on initial and final positions; distance is scalar and total path leng
th.
Define average acceleration
.
Answer:
Average acceleration = Change in velocity / Total time
Explain motion of a particle under uniform acceleration.
Answer:
The particle covers unequal distances in equal time intervals; velocity changes at constant rate.
What is a position-time graph?
Answer:
A graph showing position of an object as a function of time.
Write the vector form of displacement.
Answer:
( = _2 - _
1 )
What is projectile motion?
Answer:
Motion under gravity where path followed is a parabola.
What is instantaneous acceleration?
Answer:
It is the acceleration at a particular instant of time.
Explain the direction of acceleration in circular motion.
Ans
wer:
Always directed towards the center of the circle.
What is meant by kinematics?
Answer:
Study of motion of bodies without considering forces.
Define vector addition.
Answer:
Combining two or more vectors to get a single vector.
What is vector subtracti
on?
Answer:
Adding a vector with the negative of another vector.
What is the physical significance of a slope of position-time graph?
Answer:
It gives the velocity of the object.
Differentiate between uniform and non-uniform motion.
Answer:
Uniform motion:
constant speed; Non-uniform: variable speed.
What is the unit and dimensional formula of acceleration?
Answer:
Unit: m/s²; Dimensional formula: [L T^-2]