April14 ,2011 · Why$starts$and$glides?$$ GoSwim& 1.Lessswimmingduringlaps& 2.Lowerstrokecount...
Transcript of April14 ,2011 · Why$starts$and$glides?$$ GoSwim& 1.Lessswimmingduringlaps& 2.Lowerstrokecount...
Sonya Parashar Biology 438 301 Professor Rome April 14th, 2011
Why starts and glides? GoSwim 1. Less swimming during laps 2. Lower stroke count 3. Improvements in your swimming breakouts 4. Specifically for starts, overtake swimmers during a race that have poor push offs1.
Purpose of the Study Examine several properties of two different starts
Velocity Acceleration Force
Examine drag during gliding stage
Equipment Sheerr Pool in Pottruck Gym High Speed Camera Bathing suit Goggles Cap Permanent marker
Video of the glide
Graph of the glide
Graph of the glide
Graph of the glide
Graph of the glide
Calcula=ons 1 pound = 0.45 kilograms
Therefore, I weigh approximately 54 kilograms Maximum force = (mass) (max. acceleration) Force = (54) (2.675) = 144 N
Max. acceleration occurred at 35.16 seconds
Drag: FD = (1/2)ρv2CDA Where ρ = mass density of liquid, v = velocity, CD = drag coefficient2, A = reference area
ρ = ~1.0 kg/m3, v= velocity at different points, CD = ~0.8, A = .0646 (.393((.164))
Calcula=ons (cont.) Drag at maximum velocity (26.6) = 18.28 N Drag at second highest velocity (21.6) = 12.05 N Drag at third highest velocity (17.8) = 8.19 N Drag at fourth highest velocity (17.2) = 7.6 N
Techniques of Grab-‐start Backstroke start
Video of the grab-‐start
Graph of the Start
Calcula=ons 1 pound = 0.45 kilograms
Therefore, I weigh approximately 54 kilograms Maximum force = (mass) (max. acceleration) Force = (54) (3.65) = 197.1 N
Max. acceleration occurred at seconds 62.62 secs
Drag: FD = (1/2)ρv2CDA Where ρ = mass density of liquid, v = velocity, CD = drag coefficient, A = reference area
ρ = ~1.0 kg/m3, v= velocity, CD = ~0.8, A = .0646 Drag at 33.6 m/s = 29.2 N
Conclusions Higher velocities tend to occur when most of the body is submerged Velocity decreases as more of the body becomes exposed to the surface and less of it is covered with water
The overall drag is reduced Maximum acceleration and maximum velocity do not occur at the same time
Direct correlation of drag and velocity
Further Study Better, more aquatically suited equipment
Underwater high speed camera Outdoor pool Underwater force plates
More detailed analysis of drag Passive drag Different swimmers
References 1-‐ http://www.goswim.tv/entries/5996/all-‐strokes-‐-‐-‐simple-‐streamline.html
2-‐ Zatsiorsky, Vladimir M. Kinetics of Human Motion. Champaign, IL: Human Kinetics, 2002. Print.
3-‐ Chatard, Jean-‐Claude. Biomechanics and Medicine in Swimming IX: Proceedings of the IXth World Symposium on Biomechanics and Medicine in Swimming, University of Saint-‐Etienne, France. Saint-‐Etienne, France: University of Saint-‐Etienne, 2003. Print.