# Trouble understanding Circular Motion(Uniform and Nonuniform) concepts

1. Sep 25, 2011

### craigerymonto

Hey,
My professor introduced circular motion this last Friday in his lecture and I've spent the weekend trying to figure out the basic concepts behind it as well as the different formulas that are used. I've had a lot of trouble with this and any help would be appreciated.

2. Sep 25, 2011

### gsal

You need to get a bit more specific before anyone decides to start explaining anything.

Maybe if you would say exactly what concept/formula you don't quite understand and why you don't understand it or what it is you think it is, etc.

3. Sep 26, 2011

### Naty1

A few simple concepts should help get you started:

constant velocity is movement in a straight line and uniform speed,

uniform circular motion therefore involves acceleration as direction (of velocity) is constantly changing as rotation occurs,

in uniform circular motion acceleration is always present and the acceleration (vector) is orthogonal to the velocity (vector),

angular velocity w is to circular motion as velocity v is to straight line motion,

with a rigid rotating object, each point out from the center of rotation moves at the same angular velocity w but an increasing linear velocity [ v= wr].

And it always helps I thionk to ask yourself some questions and see if you can answer them:
maybe,
where on a rigid object in uniform circular motion are forces greatest?
If I twirl a stick from the middle, and the tip moves at "a" ft/sec, how fast is it moving half way from the tip??

Which of the following is constant on a solid rigid disc in uniform circular motion?:
a]velocity,
b]acceleration,
c]angular velocity,
d]all of the above,
e]none of the above

etc, etc

Last edited: Sep 26, 2011