Class: 9 Month: June Worksheet Number: 09/Sci/09/01
Subject: Science Chapter: 09 – Force and laws of
motion
Name:
____________________________________________
Section A: Exposition
Each question carries 1 mark :
1.
Name
the physical quantity which is related to inertia.
2.
Which
of the following has more inertia:
(i)
A
stone of mass 200 g or a cotton ball of mass 2 kg?
(ii)
A
5 Rs. coin or a 5 Rs. note?
(iii)
A
cleaver boy of mass 30 kg or a dull boy of mass 31 kg.
(iv)
an
earthen pot of 1 kg or a gold ornament of 300 g.
3.
What
is SI unit of the following quantities:
(i) Inertia (ii) Force
4.
Which
law will you use to explain the following cases;
(i)
It
is dangerous to jump out of a moving bus.
(ii)
When
a moving bus takes a sharp turn, its passengers tend to fall/leansideways.
(iii)
When
the branches of a fruit tree are shaken vigorously, fruits fall down.
(iv) When
a moving vehicle stops suddenly, the passengers are thrown in the forward
direction.
(v)
To
remove dust from a dirty carpet, it is beaten with stick.
(vi) In
coin-and-card experiment, coin placed on card falls into the tumbler, when card
is flicked sharply.
5.
Identify
the scalar quantities:
Force,
distance, displacement, mass, speed, momentum, velocity, acceleration, time
6.
Which
forces can change the state of a body - balanced or unbalanced?
7.
Which
forces can change the shape of a body - balanced or unbalanced?
8.
Identify
the vector quantities:
Time,
displacement, force, acceleration, momentum, velocity, mass, distance, speed
1
Class: 9 Month: June Worksheet Number: 09/Sci/09/01
Subject: Science Chapter: 09 – Force and laws of
motion
Each question carries 2 marks :
11.
State
Newton’s first law of motion.
12.
Define
Inertia of a body.
13.
Define
unbalanced force.
14.
Write
any two properties of action – reaction forces.
Section B: Extended Exposition
Each question carries 2 marks :
15.
Questions below refer to a coin which is
tossed straight up into the air. When it is tossed up, it moves upward, reaches
its highest point and falls back down again. Use any of the following choices
(A - G) to indicate the force acting on the coin for each of the cases
described below. Ignore any effect of air resistance on the coin.
A
The force is down and
constant.
B
The force is down and
increasing.
C
The force is down and
decreasing.
D
The force is Zero
E
The force is up and constant.
2
Class: 9 Month: June Worksheet Number: 09/Sci/09/01
Subject: Science Chapter: 09 – Force and laws of
motion
F The force is up and increasing.
G The force is up and decreasing.
J None of the answers above describes the
situation correctly.
i.
The coin is moving upward after it is released.
ii.
The coin is at its highest point.
iii.
The coin is moving downward.
iv.
The coin is in the hand of the
thrower.
Class: 9 Month: June Worksheet Number: 09/Sci/09/01
Subject: Science Chapter: 09 – Force and laws of
motion
Section C: Interpretation & Reasoning
Each question carries 1/2 mark :
17.
Mark
the statements true (T ) or false (F):
a.
If the speed of a particle remains constant, this
means no unbalanced force acts on it.
b.
Action and reaction force act on the same object.
c.
Action and reaction forces cannot cancel one
another.
d.
Newton’s first law is also called as law of inertia.
e.
If the velocity of a body is doubled, its inertia
will be doubled also.
Each
question carries 1 mark :
18.
Why
do action and reaction not cancel each other?
19.
Give
an example where two equal and opposite forces don’t form action-reaction pair.
Each
question carries 2 marks :
20.
When a force acts on an object, it
accelerates? What do you observe when two equal and opposite forces acts on an
object?
21.
A small stone is tied to one end of a
long string and made to revolve by holding the other end of the string. If the
string breaks, why does stone fly off tangentially?
22.
Explain
why it is easier to stop a tennis ball than a cricket ball moving with the same
speed.
23.
Explain
why it is dangerous to jump out of a moving bus.
24.
Draw
velocity-time graph of a moving particle on which net external force acting is
zero.
25.
Newton’s
first law states that a body in motion will continue its motion with
uniform
speed if there is no external force acting on the body, but in real life we never
experience this phenomenon. Any moving object comes to rest if external force
on it stops acting. How will you explain it?
4
Class: 9 Month: June Worksheet Number: 09/Sci/09/01
Subject: Science Chapter: 09 – Force and laws of
motion
26.
There are three solids made up of
aluminium, steel and wood, of the same shape and same volume. Which of them
would have highest inertia?
27.
The
earth attracts an apple with a force of 1.5 N. Taking this as an action force,
(i)
How
much is the reaction force?
(ii)
Who
exerts this reaction force?
(iii)
On
which body does this reaction force act?
(iv) If
apple comes in motion due to this action force, why doesn’t earth come in
motion due to the reaction force?
Each question carries 3 marks :
28.
Two balls of the same size but of
different materials, rubber and iron are kept on the smooth floor of a moving
train. The brakes are applied suddenly to stop the train. Will the balls start
rolling? If so, in which direction? Will they move with the same speed? Give
reasons for your answer.
Section D: Problem Solving
Each question carries 2 marks :
5
Class: 9 Month: June
|
Worksheet Number: 09/Sci/09/01
|
||
Subject: Science
|
Chapter: 09 – Force and laws of
motion
|
||
6
No comments:
Post a Comment