# Calculating how fast a wheel turns

1. Dec 4, 2003

### gencartmanelee

Its been over 4 years since physics, i'm a little rusty.

I am doing a cg animation of a car moving, and I can't get the wheels to look right when turning(I'm eyeballing the rotation of the wheels). The wheels look like they are turning to slow or too fast.

1)How do you determine how long it takes for a wheel to complete 1 revolution? My knowns are distance and radius of the wheels (I think that's all I'd need to know). If not, please just post a formula.

2)How is this effected when the car is accelerating?

3)How is this effected when the car is turning?

Tnx for the help, I'm sure you'll see more posts later from me on related things.

Also, is there an intro level book someone could recommend that teaches the basics of stuff like this? I don't want a book just about theory, I actually need to solve problems :)

2. Dec 4, 2003

### chroot

Staff Emeritus
A wheel moves forward a distance equal to its circumference with each rotation.

- Warren

3. Dec 5, 2003

### d00dz

2) The wheels motion is not affected by acceleration since the point of the wheel that touched the surface will always be 0 assuming that you have a non-slip condition. The only difference will be that fact that the actual wheel will be spinning faster and faster with the car.

3) Again it will have no difference ASSUMING that the turning radius is much greater then the radius of the wheel.