A sample project for Class 11 Physics on Projectile Motion.

1. DELHI PUBLIC SCHOOL
JAIPUR
PHYSICS PROJECT REPORT
PROJECTILE MOTION
GUIDED BY: SUBMITTED BY:
Dr. Richa Ma’am Sparsh Sharma
11-B(Sci.)

2. DELHI PUBLIC SCHOOL
JAIPUR
CERTIFICATE
This is to certify that the Physics project Projectile
Motion has been submitted by the candidate Sparsh
Sharma for class 11 in the year 2018. It is further
certified that this project is the individual work of the
candidate.
Teacher in-charge
Signature: Date:

3. ACKNOWLEDGEMENT
In the accomplishment of this project, many people have
provided me with heart pledged support and I want to thank all
the people who have been concerned with this project. I would
like to thank my Physics teacher Dr. Richa Sharma who guided
me to complete the project.
Last but not least, I would like to thank my parents and
friends for their help and suggestions.

4. INDEX
 Projectile Motion
o Definition
o Discovery and Evolution
 Aristotle’s Theory of motion
 Medieval Scientists
 The Renaissance
 Galileo’s Work
o Applications
 Trebuchet
o Definition
o History
o Structure
o Principle
o Working

5. PROJECTILE MOTION
Definition
Projectile motion is a form of motion experienced by an object
or particle that is thrown near the Earth's surface and moves
along a curved path under the action of gravity only.
Discovery and Evolution
Aristotle’s Theory of Motion
The Greek thinker stated that if a body is moving, something
external is required to keep it moving.
E.g.- An arrow shot from a bow keeps flying since the air behind
the arrow keeps pushing it.

6. Medieval Scientists
Aristotle’s medieval successors internalized this force in
the projectile itself and called it "impetus." This impetus
caused the object to move in a straight line until it was
expended, at which point the object fell straight to the
ground. While objects projected through small distances
may appear to behave in this manner, under closer
inspection and when viewing projectiles traveling greater
distances, it becomes clear that projectiles do not behave
in this manner.
The Renaissance
During the Renaissance, the focus, especially in the arts,
was on representing as accurately as possible the real
world whether on a 2 dimensional surface or a solid such
as marble or granite. This required two things. The first
was new methods for drawing or painting, e.g.,
perspective. The second, relevant to this topic, was
careful observation.
With the spread of cannon in warfare, the study of
projectile motion had taken on greater importance, and
now, with more careful observation and more accurate
representation, came the realization that projectiles did

7. not move the way Aristotle and his followers had said
they did: the path of a projectile did not consist of two
consecutive straight line components but was instead a
smooth curve.
Galileo’s Work
Now someone needed to come up with a method to
determine if there was a special curve a projectile
followed. But measuring the path of a projectile was not
easy.
Using an inclined plane, Galileo had performed
experiments on uniformly accelerated motion, and he
now used the same apparatus to study projectile motion.
He placed an inclined plane on a table and provided it
with a curved piece at the bottom which deflected an
inked bronze ball into a horizontal direction. The ball
thus accelerated rolled over the table-top with uniform
motion and then fell off the edge of the table Where it
hit the floor, it left a small mark. The mark allowed the
horizontal and vertical distances traveled by the ball to
be measured.
By varying the ball's horizontal velocity and vertical drop,
Galileo was able to determine that the path of a
projectile is parabolic.

8. A page from Galileo's notebooks, showing an experiment
such as the one described here.
Applications
1. Ballisticsis the science of mechanics that deals with the flight, behavior, and
effects of projectiles, especially bullets, unguided bombs, rockets, or the
like; the science or art of designing and accelerating projectiles so as to
achieve a desired performance.
2. A ballistic missile is a missile only guided during the relatively brief initial
powered phase of flight, and whose subsequent course is governed by the
laws of classical mechanics (which includes projectile motion). It plays an
important role in sports.
E.g.- Football, baseball, golf, javelin throw, discuss throw, cricket, tennis,
table tennis, basketball and rugby.
3. In materials handling industries, often times, a designer will use projectile
motion to determine the anticipated trajectory of the discharge from bulk
solids belt conveyors and bucket elevators. They use the predicted
trajectories to aid in designing material collection chutes, etc.
4. Many weapons are based on projectile motion, like catapults, slingshots
and trebuchets.
TREBUCHET
Definition
A trebuchet is a type of catapult, a common type of siege engine w hich uses a sw inging arm to throw a projectile.

9. History
1. The first recorded use of traction trebuchets w as in ancient China. They w ere probably used by the Mohists as early as
4th century BC.
2. The hand trebuchet was a staff sling mounted on a pole using a lever mechanism to propel projectiles. Basically a one-man traction
trebuchet, it wasused by emperor NikephorosII Phokas around 965 to disrupt enemy formationsin the open field.
3. The earliest known descriptionand illustration of a counterweight trebuchet comesfrom a commentary on the conquests
of Saladin by Mardi ibn Ali al-Tarsusi in 1187.
4. The couillard isa smaller version of a counterweight trebuchet with a singleframeinstead of theusual double "A"fram es. The
counterweightissplit into two halvesto avoid hittingthe center frame.
5. With the introductionof gunpowder, the trebuchet beganto lose itsplace asthe siege engine of choiceto the cannon.
Structure
In general, the trebuchet consists of a long beam that pivots around an axle
positioned above ground on a wooden structure. The axle divides the beam into a
long and short arm. The projectile is placed at the terminal end of the long arm and
pulling ropes ora counterweight is positioned at the terminal end of the short arm.
Historically, there were three basic forms of trebuchets: traction machines, powered
by crews pulling on ropes; counterweight machines, activatedby the fall of large
masses; and hybrid machines employing both pulling ropes and falling large masses.
Counterweight trebuchets were the most powerful of the three types. Large
counterweight trebuchets could throw 300 kg rocks over 200 yards. The most
massive trebuchets were reported to throw rocks in excess of 1000 kg.

10. Principle
The trebuchet relies on the principle that stored potentialenergy ofthe counterweight can be converted into kinetic energy ofthe
payload, launching it into the air. It is also based on the principle ofprojectile motion.
Working
A trebuchet works byusing the energyof a falling(andhinged) counterweight to launcha projectile (the payload), using
mechanicaladvantage to achieve a highlaunchspeed. For maximum launchspeedthe counterweight must be muchheavier
than the payload, since this means that it will "fall" quickly.
the counterweight pivots around a muchshorter distance thanthe payload end. The advantage of this is that the payloadend
of the beamreaches a muchhigher linear velocitythanthe counterweight endof the beam. Thisis the principalof mechanical
advantage, andis what allows the payload to reach a high launchvelocity. However, because the counterweight pivots around
a much shorter distance, its weight must be muchgreater thanthe weight of the payload, to get a high launch velocity.

14. BIBLIOGRAPHY
Books:
 Physics(Part1)-Textbook for class 11(NCERT)
 Galileo’s Notes on Motion by Stillman Drake
 The Art of Renaissance Science Galileo and Perspective featuring Joseph W.
Dauben
 Galileo Gleanings XXII: Galileo's Experimental Confirmation of Horizontal
Inertia: Unpublished Manuscripts by S. Drake
Websites:
 Wikipedia.org
 Galileo.edu
 Scienceexplained.com
 Quora.com
 Sciencebuddies.com
 Real-world-physics-problems.com