I'm currently doing some calcs on the land-speed of a vehicle. From my other calcs, I obtained the wheel-motor's speed in RPMs, and the tire diameter. However, when attempting to obtain the speed from MPH, the calc seems way off. I did it by hand and used an online calculator. and they both gave the correct speed. What am I doing wrong, and how do I get the correct speed calc?
Solved! Go to Solution.
I was able to figure it out. Here is the calcs for it. The diameter*pi calc in order to get the distance per rev needs to be done separately inside its own variable. I was trying to combine them in the "speed" function. Leaving this here for anyone else who comes across this problem.
I was able to figure it out. Here is the calcs for it. The diameter*pi calc in order to get the distance per rev needs to be done separately inside its own variable. I was trying to combine them in the "speed" function. Leaving this here for anyone else who comes across this problem.
Hi,
your problem is related to wrong use of rev unit.
The units "rpm" and "rev/min" have 2*pi radians included, so they refer to angular velocity. The speed of the tread of the tire is radius times angular velocity, so: