SHREE VAISHNAV ACADEMY
Integrated Project
Session: 2022-23
Subject: Physics
Topic: To Study the Newton’s Third Law of
Motion
Submitted to:
Amit Joshi
Submitted by:
Yash Patil
Certificate
This is to certify that Yash Patil student of XI Science has
successfully prepared the report on the project entitled
“To Study the Newton’s Third Law of Motion”
Under the guidance of
Amit Joshi
This report is the result of her endeavour and efforts
The report is found worthy of acceptance as the final project
for subject Physics of class XI.
Signature of Physics teacher
Signature of External Examiner
Signature of Principal
Declaration
I hereby declare that the project work entitled
“To Study the Newton’s Third Law of Motion”
Submitted to Department of Physics,
SHREE VAISHNAV ACADEMY
Is prepared by me.
YASH PATIL
XI A SCIENCE
Acknowledgement
I would like to express deep thanks of gratitude to my
project guide Amit Joshi for guiding me
Immensely through the project. Her constant guidance and
advices are responsible for the successful completion of this
project.
I would like to thanks our Principal Mrs. Richa Tiwari Diwan
for coordinating in every possible way for the project
I must appreciate my classmates as well as my dear family
for being there with me throughout the ups and downs of the
project.
Last but not the least I would like to thank all those who
helped me directly or indirectly for the completions of the
project.
YASH PATIL
XI A SCIENCE
ABSTRACT :
A variety of action-reaction force pairs are evident in nature.
Consider the propulsion of a fish through the water. A fish
uses its fins to push water backwards. But a push on the water
will only serve to accelerate the water. Since forces result
from mutual interactions, the water must also be pushing the
fish forwards, propelling the fish through the water. The size
of the force on the water equals the size of the force on the
fish; the direction of the force on the water (backwards) is
opposite the direction of the force on the fish (forwards). For
every action, there is an equal (in size) and opposite (in
direction) reaction force. Action-reaction force pairs make it
possible for fish to swim.
OBJECTIVE :
To study the Third Law of Motion using two spring balances.
THEORY :
Newton’s Third Law of Motion states: ‘To every action there
is an equal and opposite reaction’.
It must be remembered that action and reaction always act on
different objects. The Third Law of Motion indicates that
when one object exerts a force on another object, the second
object instantaneously exerts a force back on the first object.
These two forces are always equal in magnitude, but opposite
in direction.
These forces act on different objects and so they do not cancel
each other. Thus, Newton’s Third Law of Motion describes
the relationship between the forces of interaction between two
objects.
Whenever two bodies interact with each other, the force
exerted by the first body on the second is called action. The
force exerted by the second body on the first body is called
reaction. The action and reaction are equal and opposite.
For example, when we placed a wooden block on the ground,
this block exerts a force equal to its weight, W = mg acting
downwards to the ground. This is the action force. The ground
exerts an equal and opposite force W’ = mg on the block in
the upward direction. This is the reaction force.
APPLICATIONS OF NEWTON’S THIRD LAW
OF MOTION :
1.A gun recoils when a bullet is fired from it:
When a bullet is fired from a gun, the gun exerts a force on
the bullet in the forward direction. This is the action force.
The bullet also exerts an equal force on the gun in the
backward direction. This is the reaction force. Due to the large
mass of the gun it moves only a little distance backward by
giving a jerk at the shoulder of the gunman. The backward
movement of the gun is called the recoil of the gun.
2.A man walking on the ground :
He is pushing the ground backward
with some force and as per newton's
third law, the ground exerts an equal
and opposite force on the person.
3.Rowing a boat :
A boat accelerates through
the action/reaction
principle (Newton's 3rd Law). You
move water one way with your
oar, the boat moves the other way.
The momentum (=mass x velocity)
you put into the water will be
equal and opposite to the
momentum acquired by the boat.
4.A person is moving forward during swimming :
A person pushes water with his hands in the backward
direction (action) and water, in turn, pushes him forward due
to the force of reaction. Hence the forward movement in
swimming takes place because of the third law of motion.
5.Rocket propulsion :
Launching a rocket relies on Newton's
Third Law of Motion. A rocket engine
produces thrust through action and
reaction. The engine produces hot
exhaust gases which flow out of the
back of the engine. In reaction, a
thrusting force is produced in the
opposite reaction.
PROCEDURE:
1. Take two similar spring balances of different ranges, say A
and B.
2. Note the least count of the spring balances.
3. Attach the ring of spring balance A on a hook fixed in the
wall and the spring balance B is attached to the hook of spring
balance A.
4. Hold the spring balances exactly horizontal to the table.
5. Pull the ring of spring balance B gently.
6. Observe and note the reading of both the spring balances.
Repeat the experiment by applying different forces.
OBSERVATIONS:
1. Least count of the spring balance = value of 1 small
division
2. Least count of the spring balance A=………N
3. Least count of the spring balance B =…………………N
RESULT:
The readings on both the balances are the same in each case.
Thus action and reaction forces are equal and opposite and act
on two different bodies.
PRECAUTIONS:
1. Spring balance of different least count should be taken.
2. The spring balance should be brought in elastic mode
before doing the experiment.
3. The second spring balance should not be pulled beyond its
elastic limit.
4. The reading of the spring balance should be taken without
any parallax error
BIBLIOGRAPHY
 ww.slideshare.net
 https://www.seminarsonly.com/Engineering
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
Projects/Physics/third-law-of-motion.php
https://www.nasa.gov/sites/default/files/atoms/files/stem
onstrations_newtons-third-law.pdf
https://testbook.com/question-answer/the-forwardmovement-in-swimming-takes-place-becau-5fc75f8b8e7c885a20c2d175#:~:text=EXPLANATION%
3A,the%20third%20law%20of%20motion.
http://eodg.atm.ox.ac.uk/user/dudhia/rowing/physics/basi
cs.html#:~:text=A%20boat%20accelerates%20through%
20the,momentum%20acquired%20by%20the%20boat.
https://byjus.com/question-answer/a-person-is-walkingon-the-road-which-of-the-following-observation-s-is-are24/