Physics 101: Cannonball Experiment and Projectile Motion Analysis

This assignment explores the physics of projectile motion through a cannonball experiment. The experiment investigates the independence of horizontal and vertical motion, energy conservation, and momentum. The procedure involves launching a cannonball at a specific angle and measuring its trajectory using forearm measurements, which are then converted to the metric system. The results include measurements of firing angles, distances, and calculations of initial velocity and time of flight. The discussion section addresses measurement systems, control variables (gravity, mass, velocity, and firing angle), potential errors (human, systematic, and random), and the importance of standard units for accurate and precise results. The assignment highlights the practical application of physics principles and the importance of mathematical systems for expressing relationships between measurements. The report includes references to support the concepts discussed in the assignment.

Running Head: Firing a Cannonball 1
Firing a Cannonball
Student Name
Student Registration Number
University Affiliation

Firing a Cannonball 2
Overview
The firing of a cannonball is classified under the ballistics field. The projectile motion occurs
when the objects are fired at a given initial velocity or dropped from a given point and the motion of the
cannonball moves under the influence of gravity. The ballistics experiment demonstrated the
independence of the horizontal and vertical components of the motion of the object (Griffith, 2014). The
experiment is used in determining the energy conservation, momentum conservation, and projectile
motion. The experiment takes into consideration the potential energy possessed by the cannonball at still
motion and when it is being propagated. During propagation, the kinetic energy has a given velocity. This
experiment seeks to determine the measurement systems used in the determination of records for energy
computations. The firing a cannonball experiment is a common phenomenon. Young boys do the catapult
games while playing out in the field. The concept is that of projectile motion incorporating energy
systems and computations. In real life application, it is deemed as common or the casual play but in
physics it is a concept that can be used to do greater projects such as the nuclear missile projection.
Laboratory Experiment
Equipment
(i) Steel rod and trigger
(ii) Bob
(iii) Measuring tape (forearm)
(iv) Ramrod and the plunger set (fixed on the base)
Procedure
(i) Cock the spring with the ball in the barrel.
(ii) The ramrod is used to push the ball against the plunger until the mechanism latches in one of
its three range positions. To launch the projectile, the trigger was simply pushed down to

Firing a Cannonball 3
release the steel rod. The projectile was propelled into the cup at the base causing the bob to
rise into a trajectory at a given firing angle.
(iii) To avoid recoil of the bob and the pendulum apparatus, the equipment was held firmly to the
base.
(iv) The measurement in this experiment uses the span of the forearm. The number of forearms
were recorded and later computed to convert to the metric system.
Results and observations
The bob had a trajectory as illustrated below,
The table below shows the measurement collected from the different tests carried out in firing a
cannonball,
Tests Firing Angle (θ) Fore-arm Meters
1 350 3 0.36
2 350 4 0.48
3 350 5 0.60
4 350 3 0.36
5 350 4 0.48
Conversion rate

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(1 forearm = 12cm)
More information,
Mass of the bob = 4g
Height of the projectile = 14cm (0.14m)
To determine the initial height,
H= 1
2∗g t2
The time taken to get to the end of the trajectory is given as,
t= √ 2 H
g
The horizontal velocity component is constant and it is given as,
x=V o t
The initial horizontal velocity of the projectile can also be calculated by,
x=V o √ 2 H
g , V o =x √ g
2 H
Discussion
The cannonball experiment uses the measuring tap to perform the measurements. The use of the metric
systems ensures that there is uniformity in the measurement system. The physicists can use the metric
system to convert to any other of their choice as it employs the standard prefixes in the tune of 10. The
control variables are the gravity constant, the mass of the ball, the velocity of the ball, and the height it
attains during the propagation. The key control variable is the firing angle during the launch of the
cannonball.

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The difficulty that would arise in measurement is the determination of the error present especially if the
computations are quite away from the ideal measurements. Some of the experimental errors are human
errors based on personal bias, the systematic errors, and the random errors. The measurement tool used
can help improve on the accuracy and the precision. The precision determines how much spread is in the
data and ensures that the values are to their significant levels. The peer-reviewers would encounter
difficult in confirming or denying the validity of my results when they are presented in the forearm
scientific measurement system. The reason being that the forearm length is not standard. This is resolved
by converting the measurement forearm to the metric system for ease of understanding.
The measurements of one person using their own measuring system is seen as a hypothesis. It is,
therefore, very important to have the ability to express relationships between measurements.
Mathematical systems are useful as they follow a given routine. The symbols that represent quantities in
mathematical statements are a shorter and sure way of expressing ideas that involve numbers as compared
to other unregistered systems of measurement. It is easier to manipulate such symbols on a standard basis.

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References
Griffith, T. (2014). A Conceptual Introduction to Physics. In Physics of Everyday Phenomena.
New York, NY: McGraw-Hill.