# Calculate output power based on speed

• December 31st 2009, 07:01 AM
stnail
Calculate output power based on speed
I need a way to calculate power output based on known speed given the following curve for the yellow line:
[IMG]file:///C:/DOCUME%7E1/snail/LOCALS%7E1/Temp/moz-screenshot.png[/IMG]http://i242.photobucket.com/albums/f...powercurve.jpg
• December 31st 2009, 07:37 AM
CaptainBlack
Quote:

Originally Posted by stnail
I need a way to calculate power output based on known speed given the following curve for the yellow line:
[IMG]file:///C:/DOCUME%7E1/snail/LOCALS%7E1/Temp/moz-screenshot.png[/IMG]http://i242.photobucket.com/albums/f...powercurve.jpg

Are you asking for the equation of the yellow line?

CB
• December 31st 2009, 08:13 AM
stnail
What I am looking for is an equation that will give me the power if I know the speed. This doesn't have to be exact just a close estimate. I can see from the chart that 30MPH = 650 Watts. 0 MPH = 0 watts.
• December 31st 2009, 08:55 AM
CaptainBlack
Quote:

Originally Posted by stnail
What I am looking for is an equation that will give me the power if I know the speed. This doesn't have to be exact just a close estimate. I can see from the chart that 30MPH = 650 Watts. 0 MPH = 0 watts.

Try something like $p(v)=0.71 v^2$

CB