Vertical Jump - Mean Power Calculation
Moderators: Ironman, Jungledoc, parth, stuward, jethrof
Vertical Jump - Mean Power Calculation
Does anyone know how mean power is calculated for the vertical jump calculator in exrx.net.
It's physics
The fine people use the information that you supply and do something similar to what is described by this:
http://en.wikipedia.org/wiki/Power_(physics)
I don't know exactly either?
http://en.wikipedia.org/wiki/Power_(physics)
I don't know exactly either?
I can't answer your question, but it made me think of a previous discussion on here. It actually wasn't really on power, but it almost got hijacked by some, erm, debating which is why it seems a bit all over the place. but there's some great info,
Really, your looking for the discussions about power with Kenny Croxdale, who is very knowledgeable on the subject :-)
http://exrx.net/forum/viewtopic.php?t=4 ... c&start=15
Hope that helps
KPj
p,s some good links in that thread, too.
Really, your looking for the discussions about power with Kenny Croxdale, who is very knowledgeable on the subject :-)
http://exrx.net/forum/viewtopic.php?t=4 ... c&start=15
Hope that helps
KPj
p,s some good links in that thread, too.
Re: Vertical Jump - Mean Power Calculation
I can't speak for the actual calculation used in the calculator, butnelson wrote:Does anyone know how mean power is calculated for the vertical jump calculator in exrx.net.
power=work/time or forcexdistance/time
In this case, force is equal to your weight, distance is the height of the jump and time is calculated from the height and gravity.
Stu
Re: Vertical Jump - Mean Power Calculation
As mentioned here, to calculate power in Watts in a physical way:stuward wrote:I can't speak for the actual calculation used in the calculator, butnelson wrote:Does anyone know how mean power is calculated for the vertical jump calculator in exrx.net.
power=work/time or forcexdistance/time
In this case, force is equal to your weight, distance is the height of the jump and time is calculated from the height and gravity.
Stu
Power is energy dissipated per second.
Energy is work done.
Work done is force x distance.
Force is your body-weight in kilograms multiplied by upward acceleration.
Upward acceleration would need to be in excess of 9.81m/s/s.
You could work out the minimum power produced by:
Multiplying body-weight by 9.81 then multiply by change in height. With this answer divided by the time taken.
To get the absolute power you would need to know your final upward velocity.
A simple although not entirely accurate way would be to calculate the gain in potential energy, which is the (change in height) x (acceleration due to gravity) x (body-weight). Then divide the potential energy by the time taken to produce the change in height.
Example: Person of weight 100 kg. Gravity is 9.81m/s/s. Change in height 1m. Time taken 0.5s.
100 x 9.81 x 1 = 981 Joules
981 / 0.5 = 1962 Watts
I had to plug your numbers into the calculator to see if it gave the same answer. It didn't. It gave 2401.
I found this site:
http://www.topendsports.com/testing/ver ... -power.htm
They had 4 different calculations, all gave different answers and all were different than the calculator.
I found this site:
http://www.topendsports.com/testing/ver ... -power.htm
They had 4 different calculations, all gave different answers and all were different than the calculator.
What I said was a raw theoretical analysis. Calculate the power by working out the change in potential energy and dividing that by the time taken to do so. It does not take other factors into consideration such as momentum, air resistance etc.stuward wrote:I had to plug your numbers into the calculator to see if it gave the same answer. It didn't. It gave 2401.
I found this site:
http://www.topendsports.com/testing/ver ... -power.htm
They had 4 different calculations, all gave different answers and all were different than the calculator.
Vertical Calculation
Thanks for the responses.
I tried to calculate the power using potential energy or using kinetic energy, but my calculations were way off what was in ExRx.net.
I though if I found it on the internet it must be true.
I tried to calculate the power using potential energy or using kinetic energy, but my calculations were way off what was in ExRx.net.
I though if I found it on the internet it must be true.
JD, I think you are right. I've seen this topic on the vertical come up many times. Most often, what is recommended are fairly heavy squats, to estblish a strength base in the hips/glutes/quads, followe by some OL pulling motions from the floor, and some 2nd pull variations. The 2nd pull is basiclly kicking the hips in combined with a jump shrug with a heavy barbell. This works pretty well. However, when it comes to Vertical Jumps for basketball stuffing, LOL, the best method I've ever seen came from a women's Basketball coach, and she went and bought one of those adjustable hoops, and then had the gals stuff at a given hieght, and then slowly raised the bar = so to speak. She didn't worry, or care, about scientific studies, she just got her ladies out there and adapting to the height increases.
Tim
Tim