STAGE 1: Planning Your Investigation
Badminton is unlike many other racket sports as instead of using an ordinary spherical ball it uses a cone shaped projectile called a shuttlecock (Julien Le Personnic, 2011). The shuttlecock is made with a weighted tip and synthetic or feather outer cone (May Kawn, 2013). This design is a phenomenon as the projectile (shuttlecock) acts vastly different from an ordinary ball as despite a player being able to hit a shuttlecock to impressively high initial velocities, it’s feathers or synthetic cone creates incredibly high drag the drastically slows down the projectile in the air as it creates a lot of air resistance (Ken, 2012)(Julien Le Personnic, 2011). This raises a question of to what extent does the aerodynamic structure of the shuttlecock affect the distance it can travel.
(Accs, 2018)
Like most racket sports, badminton is heavily impacted by the force of gravity. Gravity affects all components of the sport such as the parabolic trajectory of its projectile motion when travelling through the air, how high the shuttlecock bounces off of the racket upon impact, how fast the velocity of the shuttlecock is and what motion it produces while travelling through the air (Physics Classroom). All of these factors need to be taken into account in the sport however they are not nearly as impactful, as the physics concept of air resistance.
As mentioned previously a shuttlecock is a high drag projectile which means that air resistance plays a key role in determining how far a shuttlecock will travel (Julien Le Personnic, 2011). Air Resistance determines how much force is needed to allow for a shuttlecock to fly through the air without stopping. This is because air resistance is a force of friction that is exerted by the air onto a projectile that slows down its velocity (Matt Williams, 2016). The greater the air resistance the faster a projectile will slow down in the air until it reaches a halt. An object with a large cross sectional area or an object travelling at high speeds will experience a larger amount of air resistance (Victoria Glemu). Due to the high drag properties of the shuttlecock it means that it dramatically decreases in velocity whilst in the air. This is because the design of the shuttlecock allows for air to travel through gaps in the synthetic or feather cone which increases the amount of air resistance received as more air can flow past and through the shuttlecock. The image to the left shows how air flows past the shuttlecock and causes friction (The Student Room, 2007). As seen the outer cone causes a larger area for the air to exert a force against.
Air resistance is an important part of understanding the sport as it explains how the area of an object affects how fast it travels. For example, according to the law of gravity two pieces of paper with the same mass would hit the ground at the same time. However if one of those pieces of paper were scrunched up it would hit the ground faster than the other flat piece of paper (Wendy McDougal). This is all to do with air resistance as it represented in the formula below:(Softschools, 2012). As shown in this formula the higher, the cross sectional area of the projectile will be larger and therefore the total amount of air resistance will be also be larger. This also applies to a projectile’s velocity as seen in the formula (Softschools).
Air resistance has a substantial impact on projectile motion as it can drastically steepens the shuttlecocks trajectory (Julien Le Personnic, 2011). A projectile is defined as any object that is dropped or thrown that continues its motion from its own inertia as it is impacted by the force of gravity (Physics Classroom). Most projectiles such as a shuttlecock travel through the air in a parabolic curve. This is because when an object travels through the air its velocity is on a steady decline due to forces like air resistance and since gravity is present it pulls a projectile back down to the ground (Physics Classroom). The effect of gravity on projectile motion can be seen in the image to the right (Physics Classroom).
This is due to Newton’s 2nd law of momentum as it defines how much force is needed to stop a projectile. If an object with mass is in motion than it has momentum as momentum is defined as “mass in motion”(Physics Classroom). This is a key factor in determining how much air resistance is exerted onto the shuttlecock.
Projectile motion is also heavily affected by the angle at which it is projected and the initial velocity. As seen in the diagram the angle at which a projectile is projected, has a substantial impact on the horizontal distance travelled (Research the Topic, 2018). Launch angle determines the distance travelled, height, velocity throughout the travel and time of flight (Lumen Learning). It can be seen that some angles such as 75 and 15 degrees both have the same horizontal distance travelled. This is due to the impact of initial velocity on projectile motion. When the projectile is projected at 75 degrees, it will be at a high angle that slows down the velocity quite a lot when travelling through the air due to the long travel time. When the projectile is projected at 15 degrees, it will be at such a low angle that it can not travel far into the sky and due to gravity it will hit the ground quite fast.
Considering the impact of air resistance on how a shuttlecock moves will be used to test what effect changing the aerodynamic structure of a badminton shuttlecock will have on how far it travels when dropped from a consistent height onto an angled badminton racket as seen in the diagram below (Geogebra, 2018).This will be used to investigate the relationship between the independent variable of the changing the cross sectional area of a shuttlecock and the dependant variable of how far a shuttlecock travels. Therefore if the shuttlecocks cross sectional area is decreased then there will be less air resistance and the shuttlecock will travel further because when the cross sectional area of a projectile is decreased it will decrease the amount of air resistance as the air will have a smaller area to exert a force against. This hypothesis will test the phenomenon as it will gradually decrease the cross sectional area on the shuttlecock by cutting around the outer cone in small increments. This in turn should decrease the amount of air resistance the projectile experiences and should allow it to maintain higher velocities for longer distances. This is because as previously shown the larger amount of cross sectional area there is for air to exert a force on the slower a shuttlecock will go. Therefore strengthening the hypothesise claim that a smaller area will result in a smaller amount of air resistance.
References
Softschools (2012) Air Resistance Formula, Retrieved from:
http://www.softschools.com/formulas/physics/air_resistance_formula/85/
Julien Le Personnic (2011) Flight trajectory simulation of badminton
shuttlecocks, Science Direct Retrieved from: https://ac.els-cdn.com/S1877705811010101/1-s2.0-S1877705811010101-main.pdf?_tid=2ceaf060-7326-4905-8437-c5fe92eb5ee2&acdnat=1532393598_3e03fc314ab0b0b93cd9cd8578a7f8dc
Richard Fitzpatrick (2011) Projectile Motion with Air Resistance,
Farside.com, Retrieved from: http://farside.ph.utexas.edu/teaching/336k/Newtonhtml/node29.html
Accs (2018)LOTKI TECH 350 SZYBKIE BIAŁE,
ACCS, Retrieved from: https://www.accs.sklep.pl/pl/p/LOTKI-TECH-350-SZYBKIE-BIALE/205
Matt Williams (2016) WHAT IS AIR RESISTANCE?, Universe Today,
Retrieved from: https://www.universetoday.com/73315/what-is-air-resistance/
May Kawn (2013) The Physics Behind the Badminton Shuttlecock,
Illumin, Retrieved from: http://illumin.usc.edu/assets/submissions/702/WRIT%20340_Kwan_Wing_Paper%20%232.pdf
Victoria Glemu (N/A) HOW DOES AIR RESISTANCE FORCE WORK?,
Thomastownps.vic.edu.au, Retrieved from: http://www.thomastownps.vic.edu.au/app/webroot/uploaded_files/media/how_does_air_resistance_force_work_vic_s.pdf
Wendy McDougal (2018) What is Air Resistance?, Study.com, Retrieved
from: https://study.com/academy/lesson/what-is-air-resistance-lesson-for-kids.html
Ken (2012) Types of Badminton Shuttlecocks, Shuttlecocks Online,
Retrieved from: http://shuttlecocksonline.com/types-of-badminton-shuttlecocks/
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http://www.physicsclassroom.com/class/vectors/Lesson-2/What-is-a-Projectile
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https://i.warosu.org/data/sci/img/0065/97/1403063489836.png
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http://www.physicsclassroom.com/Class/momentum/u4l1a.cfm
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ttps://qph.fs.quoracdn.net/main-qimg-c9a2bb530e22fc5e2fbf3359aef7980f
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