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Class: 9
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Month: April
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Worksheet Number: 9/Sci/08/01
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Subject:
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Physics
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Chapter: 8 – Motion
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Name:
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MOTION
SECTION - A
1.
What
are the two activities happening in the beginning of the video and at which
place?
2.
What
are the examples of linear motion and rotatory motion mentioned in the video?
3.
Define
motion.
4.
Write
any three differences between distance and displacement.
5.
Define
uniform motion. Give its two examples.
6.
Define
non uniform motion. Give its two examples.
7.
How
speed of a body in non-uniform motion is calculated?
8.
What is the term used for a body whose (i)
velocity is increasing. (ii) velocity is decreasing.
9.
A ball is dropped from some height. What are
the distances travelled by the ball (I) at the end of 1 sec (ii) at the end of
3 sec (iii) at the end of 5 sec?
10 For the ball dropped from some height. What
are the velocities of the ball
a
(I)
at the end of 1 sec (ii) at the end of 2
sec (iii) at the end of 3 sec?
b
What
is the common pattern between these values?
SECTION B (MCQ)
Choose the correct alternative
1
A
quantity has value – 6.0 m/s. It may be the -
a.
Speed
of a particle.
b.
Velocity
of a particle.
c.
Acceleration
of a particle
d.
Displacement
of a particle
2
A
body moves with a uniform velocity. This means
e.
Body
must be at rest.
a.
Body
moves along the curved path.
b.
Body
moves along a circle.
c.
Body
moves along a straight line.
3
Units
of uniform speed and non-uniform speed are
a.
m/s, m/s2
b.
m/s, m2/s
c.
m/s, m/s
d.
m/s,
km/s
1
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Class: 9
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Month: April
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Worksheet Number: 9/Sci/08/01
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Subject:
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Physics
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Chapter: 8 – Motion
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4
A
particle is travelling with a constant speed. This means
a.
its
position remains constant as time passes.
b.
it
cover equal distances in equal time intervals.
c.
its
acceleration is zero.
d.
it
does not change its direction of motion.
5
The
distance time graph of body coincides with its time axis. The body must be:
a.
in
uniform motion
b.
at
rest
c.
in
uniform accelerated motion
d.
having
non uniform acceleration
6
The
area under a graph between two quantities is expressed in m/s. The quantities
are
a.
speed
and time
b.
distance
and time
c.
acceleration
and time
d.
velocity
and time
7
Which
of the following statement is not true for a body, which has zero displacement?
a.
Body
may be is at rest
b.
Body
must have returned to its initial position
c.
Body
must have zero acceleration
d.
Body
must have zero speed
8
Velocity
of an object can be changed by changing
a.
The
speed of the object
b.
The
direction of the motion of the object
c.
Both
speed and direction of the motion of the object
d.
Both
(a), (b),(c) are true.
9
What will happen to the speed of an object if
its acceleration and velocity are in the same direction?
a.
Increases
b.
Decreases
c.
Remains
the same
d.
Becomes
zero
10
Statement I- An object moving with constant
speed can be accelerated. Statement II- Acceleration is equal to the rate of
change of speed.
A.
Statement
I is correct and statement II is correct explanation of the statement I.
B. Statement
I is correct but statement II is not the correct explanation of the statement
I.
C.
Statement
I is true but statement II is not true.
D.
Statement
I is not true but statement II is true.
a.
A
b.
B
2
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Class: 9
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Month: April
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Worksheet Number: 9/Sci/08/01
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Subject:
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Physics
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Chapter: 8 – Motion
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c.
C
d.
D
11
For
a moving body, the numerical ratio between distance and displacement is.
a.
Always
less than one
b.
Always equal to one
c.
Always more than one
d.
Equal to or less than one
13
Retardation
is the
a.
Negative speed
b.
Negative velocity
c.
Negative acceleration
d.
Negative displacement
14
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
15
A body is moving on a circle of radius r.
What will be its displacement after covering half of the distance on the
circle.
a.
Zero
b. 
r
r
c.
2 r
d.
2 r
16
Statement I- There can be displacement of an
object even in the absence of force acting on it.
Statement II- An object in
uniform motion in a straight line shows displacement even Acceleration is equal
to the rate of change of speed.
a. Both
Statement I and II is correct and statement II is correct explanation of the
statement I.
3
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Class: 9
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Month: April
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Worksheet Number: 9/Sci/08/01
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Subject:
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Physics
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Chapter: 8 – Motion
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E. Both
Statement I and II is correct but statement II is not the correct explanation
of the statement I.
F.
Statement
I is true but statement II is not true.
G.
Statement
I is not true but statement II is true.
17
Four cars A, B, C and D are moving on a
straight road. Their distance-time graphs are depicted in the given graph.
Choose the correct statement.
a.
car
A has more speed than car D
b.
car
B is the slowest
c.
car
D has speed more than car C
d.
car
B is the slowest
1
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Class: 9
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Month: April
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Worksheet Number: 9/Sci/08/01
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Subject:
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Physics
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Chapter: 8 – Motion
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SECTION C
1
Define
the following:
1. Distance --
2. Velocity –
3. Acceleration –
4. Displacement –
5. Speed –
2
A particle moves 3 m north, then 4 m east and
finally 6 m south . Calculate total distance travelled and displacement of the
particle.
(i)
Distance
travelled –
(ii)
Displacement
–
3
Displacement can be zero when distance
travelled is not zero. But when distance travelled is zero, displacement must
be zero. Justify.
4
Give two examples of each of the following
cases from your personal observations in everyday life.
(i)
A
body undergoing uniform motion
(ii)
A
body undergoing non uniform motion
(iii)
Acceleration
is in the direction of motion.
(iv)
acceleration
is against the direction of motion
5
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 here. Plot a velocity–time graph for the same.
5
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6
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Complete the given table.
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Quantity Scalar/Vector Reason for labeling it Scalar/Vector
Speed
Acceleration
Displacement
Velocity
Displacement
Time
8
Write
any three uses of velocity time graph for a non uniform motion.
9
A
car is moving with a velocity of 60km/h. How much distance will it cover in 5
minutes?
10
Name
the physical quantity which is related to,
(i) decrease in velocity
in the straight line motion.
(ii) distance travelled in
unit time.
(iii) increase in velocity.
(iv) change in velocity in
a circular motion.
(v) straight line
distance between initial and final position.
11
A driver of a car travelling at 52 km/ h
applies the brakes. The car stops in 5 s. Another driver going at 3 km/ h in
another car applies his brakes slowly and stops in 10 s. On the same graph
paper, plot the speed versus time graphs for both the cars.
12
A bullet moving with 10 m/s hits the wooden
plank. The bullet stops after penetrating the plank 2 cm deep. Calculate the
retardation of the bullet.
13
Write
the equation of motion which is a relation between,
(i) final
velocity and displacement.
(ii) displacement and
time.
(iii) final velocity and
time.
6
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Class: 9
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Month: April
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Worksheet Number: 9/Sci/08/01
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Subject:
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Physics
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Chapter: 8 – Motion
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14 ______________________________________________
15
Derive
all three equations of motion graphically.
16
Two trucks are moving at 40 mph and 50 mph
speed respectively. If the second truck starts 5 miles behind the first truck,
how long will it take for the second truck to overtake the first one?
17
Akash drove his car with a speed of 30km/hr
while going to his office. When he returned home along the same route, the
speed was 50km/hr. calculate the (i) average speed (ii) average velocity of the
car for the entire journey
18
An
insect moves along a circular path of radius 10 cm with a constant speed. If it
takes
1 minute to move from a
point A on the path to the diametrically opposite point B, find
i.
The
distance covered
ii.
The
displacement of the insect if AB represents North- south direction.
iii.
The
speed
iv.
The
average velocity
SECTION D (HOTS)
1
State which of the following situations are
possible and give an example for each of these:
(a) An object with a
constant acceleration but with zero velocity
(b) An
object moving in a certain direction with acceleration in the perpendicular
direction.
7
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Class: 9
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Month: April
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Worksheet Number: 9/Sci/08/01
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Subject:
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Physics
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Chapter: 8 – Motion
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2
A boy runs along a straight path for the
first half time with a velocity and
the second half time with a velocity . Show
that his average velocity can be given by relation
+
3
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?
4
Obtain a relation for the distance travelled
by an object moving with a uniform acceleration in the interval between 4th and
5th
seconds.
5
Two stones are thrown vertically upwards
simultaneously with their initial velocities u1 and
u2
respectively. Prove that the heights reached by them would be in the ratio of u12: u22 (
Assume upward acceleration is –g and downward acceleration to be +g ).
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(a)
The bus drives from its depot, without stopping, along the straight road to the
football ground. Find,
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...................(i)thedisplacementfromthebusdepottothefootballground,distance=
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km
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(ii) the time taken, in hours, to
travel from the bus depot to the football ground,
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.......................................time=
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hours
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(iii) the Velocity, in km /hour, of
the bus on its journey to the football ground.
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..................................speed=
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km / hour
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(b) State
how you can tell from the graph that the bus travelled at a constant velocity
to the football ground.
(c) The bus
returned to the depot by the same route, stopping a number of times to let
supporters get off near to their home villages.
(i) At how many villages
did the bus stop?
(ii) What was the smallest
displacement from a village to the football ground?
displacement =
........................................... km
9
A Car is travelling at 20 m/s along a
road. A child runs out into the road 50 m ahead and the car driver steps on the
brake pedal. What must the car's deceleration be if the car is to stop just
before it reaches the child?
10
The given figure shows the position of a
body at different times. Calculate (i) the speed of the body as it moves for 0
to 5 s (ii) 5 to 7 s (iii) 7 to 9 s.
9
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Class: 9
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Month: April
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Worksheet Number: 9/Sci/08/01
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Subject:
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Physics
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Chapter: 8 – Motion
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11
The above graph gives the distance
covered by a bus after every 15 minutes. What can
you conclude about the motion of a
body? Explain.
A train is travelling with uniform acceleration a. The
engine of the train crosses a pole 12 with a velocity u while the last coach
crosses the same pole with a velocity u. Show that
the middle of the train will cross the
pole with a velocity
Drill Exercise
1.
Converting
metre per seconds to kilometre per hour
_______
metre = 1 kilometre
_______
minute = 1 hour
_______
second = 1 minute
10
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Class: 9
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Month: April
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Worksheet Number: 9/Sci/08/01
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Subject:
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Physics
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Chapter: 8 – Motion
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_______ second = 1 hour
1. Convert the following speeds
measured in km/h to m/s using relation 1 km/h = 5/18
m/s
a) 72
km/hr = e)
240 km/hr =
b) 60 km/hr = f) 1800 km/hr =
c)
120 km/hr = g)
5km/hr =
d) 40 km/hr = h) 14km/hr =
2. Convert the following speeds
measured in m/s to km/hr using the relation 1 m/s =
18/5 km/h
a)
10m/s = b)
14m/s =
c)
15m/s = d)
48m/s =
e) 20 m/s = f) 2 m/s =
3. Practice equations of motion as
stated below.
3rd Equation -
_______________________________________________________________
1st Equation -
_______________________________________________________________
2nd Equation -
_______________________________________________________________
1st Equation -
_______________________________________________________________
3rd Equation -
_______________________________________________________________
2nd Equation -
_______________________________________________________________
1st Equation -
_______________________________________________________________
2nd Equation -
_______________________________________________________________
3rd Equation -
_______________________________________________________________
2nd Equation -
_______________________________________________________________
11
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Class: 9
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Month: April
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Worksheet Number: 9/Sci/08/01
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Subject:
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Physics
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Chapter: 8 – Motion
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PRACTICE QUESTIONS
1
What
does a speedometer of an automobile measure?
2
Estimate the displacement of a car which
attains a velocity of 54 km/hr in 20 seconds starting from rest
4
Give
an example to differentiate between uniform and non-uniform speed?
5
An object undergoes an acceleration of 8m/s2
starting from rest. Find the distance travelled in 1 second.
6
When a body falls freely under the influence
of gravity, which physical quantity remains constant?
7
A car travels 10 m in 5 seconds and 15 m in
next 10 seconds and 35 m in the last 10 seconds. Find the average speed of a
car.
8
A bus is moving at a speed of 64km/h. The
driver sees a child at a distance of 50m and applies a brake just before the
child. Find the acceleration.
9
A child completes a circular track of 200m
length in 10 s. Find the speed and velocity 10 Derive graphically the third
equation of motion.
11 A
train starting from rest attains a velocity of 20 m/s in 2 minutes. Assuming
that the acceleration is uniform, find acceleration and distance travelled by
the train, while it attained this velocity.
12
Derive the equation of motion for a position-time relation of a body moving
with uniform velocity.
13 Starting from
rest, a cyclist attains a velocity of 60 m/s in 300 seconds. If he applies
brake and slows down to rest at the rate of 2 m/s. Find
i. The acceleration in first 200 seconds.
ii.The
time taken to come to rest in deceleration. iii.The displacement in the whole
journey.
12
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