# Homework Help: Equation of frequency

1. Oct 30, 2006

### fizixisannoying

Someone help!!!

"Obtain an equation for the frequency in terms of tension, radius, and mass"

I'm having serious trouble with this question.

By the way...this is grade 12 physics...

2. Oct 30, 2006

### Pete81t

I'm not sure if this is correct, but I came up with the formula frequency (f)= square root (tension+weight)/2pi*radius*sqareroot (mass). This would be the frequency expressed in terms of tension, radius, and mass at the top of a vertical circle, but I'm not sure whether this pertains to your situation or not.

3. Oct 30, 2006

### fizixisannoying

this was for a horizontal circle...would the equation be the same?

btw, thank you!

4. Oct 31, 2006

### Chi Meson

Pete is evidently considering a verticle circle. For an ideal horizontal circle the situation is simpler (in ideal conditions, you don't consider the gravity pulling the string downward, and the length of the string can be considered to be equal tot he radius).

The tension in the string is what provides the Fc, so therefore the formula for Fc is manipulated to find a statement for v.

Then this result is equated to the basic equation for tangential speed (you know, circumference over period, or circumference times frequency).

BTW, Pete: hold back on simply giving out an answer. THis forum is for helping others, not just giving them answers. Good solution still (but for the wrong problem).