Swing Efficiency Comparison: Bubka, Tradenkov, Lavillenie
Posted: Sat May 17, 2014 5:19 pm
Because someone asked...
Yes, it is a good starting point. But the problem is that we are talking about a very complex system with an almost hidden amount of energy being controlled by gravity. As I said, the gravity component in the pole is regulated by the vaulters swing angle which is changing, which makes the system into one in which differential calculus is needed. This is why most people would want to avoid the problem if thinking about how gravity effects the vaulter + pole system.
But the totality of your thought and process is a correct starting point for determining efficiency.
Bubka 6.15m 80kg 9.94 m/s
Tradenkov 6.01m 78kg 9.47m/s
Lavillenie 6.16m 69kg 9.49 m/s
Lavillenie take off speed comes from here...
viewtopic.php?f=38&t=44165
The others come from the PVP 6m club chart.
PE = mgh
Bubka = 80kg x 9.8m/s/s x 6.15m = 4822j
Tradenkov = 78kg x g x 6.01m = 4594j
Lavillenie = 69kg x g x 6.16m = 4165j
KE = 1/2 m x v squared
Bubka = 1/2 x 80kg x 9.94 m/s x 9.94m/s = 3952j
Tradenkov = 1/2 x 78kg x 9.47m/s x 9.47m/s = 3498j
Lavillenie = 1/2 x 69kg x 9.49m/s x 9.49m/s = 3107j
Total take off to clearance gains...
Bubka 870j
Tradenkov 1096j
Lavillenie 1058j
Efficiency as PE/KE
Bubka = 4822j/3952j = 122%
Tradenkov = 4594j/ 3498j = 131%
Lavillenie = 4165j/3498j = 134%
Of course one can bring up clearance height. I can't do anything but with the numbers I'm given here. Also, this outcome is not so much an indictment of the PB model, as of Bubka's placement in it. I have contended that his speed actually allowed him to be less swing efficient, and this somewhat bears me out.
Hope that helps...
Will
P.S. I included Tradenkov as I continually find him fascinating as one of the slowest men to vault 6m and because I believe he had to diverge somewhat from elements of the PB model by regulation of his swing speed and use of tuck.
P.S.E. To get to 130% efficiency Bubka would have to clear 6.55m from a take off velocity of 9.94m/sec...
Common sense told me it took a certain amount of energy to lift Bubka 20 ft. I needed to determine what that was. I did. I knew a large percentage of that energy was generated in the Runway. I determined how much that was. I understand runway energy is stores in the Vaulter pole/system.I figured if I subtracted the energy generated in the runway from the energy required to raise Bubka 20 ft the remaining energy would be what Bubka produced from swinging, Pulling, Pushing Etc. after he left the ground. Make sense?
Yes, it is a good starting point. But the problem is that we are talking about a very complex system with an almost hidden amount of energy being controlled by gravity. As I said, the gravity component in the pole is regulated by the vaulters swing angle which is changing, which makes the system into one in which differential calculus is needed. This is why most people would want to avoid the problem if thinking about how gravity effects the vaulter + pole system.
But the totality of your thought and process is a correct starting point for determining efficiency.
Bubka 6.15m 80kg 9.94 m/s
Tradenkov 6.01m 78kg 9.47m/s
Lavillenie 6.16m 69kg 9.49 m/s
Lavillenie take off speed comes from here...
viewtopic.php?f=38&t=44165
The others come from the PVP 6m club chart.
PE = mgh
Bubka = 80kg x 9.8m/s/s x 6.15m = 4822j
Tradenkov = 78kg x g x 6.01m = 4594j
Lavillenie = 69kg x g x 6.16m = 4165j
KE = 1/2 m x v squared
Bubka = 1/2 x 80kg x 9.94 m/s x 9.94m/s = 3952j
Tradenkov = 1/2 x 78kg x 9.47m/s x 9.47m/s = 3498j
Lavillenie = 1/2 x 69kg x 9.49m/s x 9.49m/s = 3107j
Total take off to clearance gains...
Bubka 870j
Tradenkov 1096j
Lavillenie 1058j
Efficiency as PE/KE
Bubka = 4822j/3952j = 122%
Tradenkov = 4594j/ 3498j = 131%
Lavillenie = 4165j/3498j = 134%
Of course one can bring up clearance height. I can't do anything but with the numbers I'm given here. Also, this outcome is not so much an indictment of the PB model, as of Bubka's placement in it. I have contended that his speed actually allowed him to be less swing efficient, and this somewhat bears me out.
Hope that helps...
Will
P.S. I included Tradenkov as I continually find him fascinating as one of the slowest men to vault 6m and because I believe he had to diverge somewhat from elements of the PB model by regulation of his swing speed and use of tuck.
P.S.E. To get to 130% efficiency Bubka would have to clear 6.55m from a take off velocity of 9.94m/sec...