1.0 INTRODUCTION
A major premier league club is calling for a review of the allowable pressure range for the game balls after losing a penalty shootout. The
club claims that their chances of winning were adversely affected as the ball kicked by their main striker was reportedly softer than the
other balls used during the shootout and that this reduced the speed of the ball as it left the strikers foot. The balls were all within the
allowable pressure range (0.6-1.1 atm); however, the club believes that the range is too wide
2.0 TASK
You have been asked to investigate the appropriateness of the current pressure range with consideration of the differences in the
performance of the ball as a function of pressure.
In order to fulfil the requirements of your task you must:
1. Search the available literature (start with your text book) to determine a coefficient which can be used to determine separation
velocity if the velocity of the impact (strikers foot speed when hitting the stationary ball) is known
2. Design an experiment to extract this coefficient from the ball over a pressure range of 0.5-1.2 atm.
3. Tabulate your results with a quantified measure of the uncertainty in your results
4. Based on your results discuss the appropriateness of the current pressure range.
The engineers have also asked you to explain any notable phenomena in your results and any possibly limitations to you technique.
3.0 ALLOWABLE EXPERIMENTAL EQUIPMENT
For this study you are only allowed to use the following experimental equipment:
A sound recording device (no video)
PC with audio analysis software (eg. Matlab, audacity, etc.)
Hint: In designing your experiment you should consider the use of projectile motion relationships which include time and velocity.
4.0 MARKING SCHEME
Report Structure ____ 10%
Use of Literature (including appropriate referencing) ____ 10%
Writing Style (including clarity, conciseness, grammar and appropriate
referencing) ____ 15%
Results Presentation and Accuracy ____ 20%
Description of experimental and analysis methods ____ 25%
Logic and critical thought (including your interpretation of results) ____ 20%
Total ____ 100%
See Harvard reference guide for required referencing style.
Do not write in the first person or present figures, solutions, etc. which are drawn by hand. Any figures which are not
discussed will not be marked.