CANNON Essay Example

Aim and component of cannon designs

The objective of the experiment was to design and develop a prototype to address the requirements where the cannon can eject the ball over the wall at given angles. The requirements include designing a prototype that allows a machined joint using the energy stored or pressure to facilitate the anticipated movements. In this case, the motion requirements include the cannon having the capability to drive an incline that has contact with the wall and ejects the golf ball over it (Griffith & Juliet, 2011).

Multiple Cannon design

Two main designs were considered.

  1. Catapult Design

The catapult design presents the design where the mouse trap is used to trigger and propel the ball since the off shelf component helps meet the requirements of the prototype development. The catapult is readily available in the market, it is cheap and reliable. The challenge is the calculations, where attaining the torque to achieve anticipated rotation for the set requirements.

  1. Basic Cannon Design (It is the selected design, as discussed below)

Technique to choose one design

The device should drive up an incline, while making contact with a wall to eject a golf ball over it, which is what led to the selection of the prototype given below. The prototype was designed using wood and the cannon had a plastic pipe with a spring installed inside it to store the energy required to trigger the projectile motion of the ball (Griffith & Juliet, 2011).

Additionally, the selection also considered the complex setup and calculation needed for the designs. The cannon would be expensive to set up, complex calculation to track torque and rotation to achieve the anticipated goal, while the cannon is less expensive and easy calculations are needed for the objective to be attained. The cannon can be developed easily when one has the acceptable dimension and weight.

cannon cannon  1

I anticipated using 220 mm long pipe to fill it with a long spring since it would store more energy. However, the long pipe for the canon surpassed the specifed limits to car height needing a shorter pipe that was used; the 130mm pipe.


The important factors that were considered during the development of the prototype included the type of the ball that would be ejected, the angles that the ball would be launched and the pull-back distances for the angles as well. The cannon should handle the stress (load) that it is meant to carry on the maximum size. For instance, the distance the ball travels is dependent on the compression or uncompressed pressure that the spring encounters. Based on the figure below, the following calculations determing how much the spring should be compresed for the ball to go a given distance (Giancoli, 2005).

cannon  2

in the figure above, the wall height =400mm and height from bottom of cannon to the top of the wall is 340mm and add 50mm diameter of ball and 30mm gap

So, height to clear is 400-60+50+30 which is h=420mm

The projectile motion is given through the application of the force exerted on the spring and will be shown in the figures below. It is given in the compression state of the spring. The compression is also identified as the spring force, though it can be displaced or constant depending on the machine (Giancoli, 2005). As will be shown in the calculations below, the velocity of the projectile is calculated to give the potential & kinetic energy used to trigger the ball motion. When the spring is pulled back, the energy stored should be equal to the kinetic energy released used to trigger the motion of the ball. The cannon designed will be used to launch the ball in different angles, which stipulates that the distances of the projectile motion are calculated as well. The angle of the projectile is calculated including the lengths of the distances to accommodate the different angles needed (Griffith & Juliet, 2011).

cannon  3

cannon  4

At Lunch state, the following calculations were used.

Using the above figures, the air resistance is ignored in the equation of motion.



Potential energy stored in the compressed spring

U spring= cannon  5

cannon  6 U spring =
cannon  7

cannon  8

U spring =0.207 J

Potential energy due to gravity

cannon  9

= 0.05 *9.8 *0.056

U gravity =0.02744

The platform of the pipe rests on the top part of the spring, which helps in compressing the spring to allow the ejected ball to move different distances. The cannon movements will help to change the angles of launching the ball. The cannon should have enough volume/ pressure to launch the projectile at different angles. The cannon should have a barrel attached to it for the projectile to be launched at different angles.


Calculate the needed angle to clear the wall

Range = 0.266

Height = 0.320

X = V COS (cannon  10 (t)

cannon  11

cannon  12

0.320 = cannon  13

0.320 = cannon  14

cannon  15

When cannon  16 so will not clear the wall.

cannon  17

So will clear the wall.

cannon  18

So will not clear the wall.

Y bigger than 0.0300 is the needed to clear the wall

cannon  19

Optimisation of design

The calculations given above helped determine the needed K to eject the ball to the given distances above. It was tested physically by launching the cannon ball, which was successful in contacting the wall and ejecting the ball over it at the given K.

The experiment included the models of dimensional projectile motion, conservation of energy and pysics laws, which are important in launching the ball at a given angle, velocity and height. One can control the angle of the initial speed needed to drive the ball out of the cannon. The cannon is designed to eject a ball made of steel material, it is designed to operate at different angles mainly 60o 65o, 70o, and 75o, among others with minor adjustments. The compression of the spring is to be done manually, while specifying the distance the ball should go, where the diameter of the compressor also determines the distance the ball will go (Griffith & Juliet, 2011). The prototype projectile developed had accurate results, though some improvements could be implemented to improve the launching process through automating the process of releasing the pullback mechanism.


Giancoli, D. C., 2005. Physics: principles with applications. New York: Pearson Education.

Griffith, W. T. & Juliet, W. B., 2011. The physics of everyday phenomena. New York: McGraw Hill Higher Education.