# String tension, is this the correct formula?

1. Feb 26, 2004

### ant0

I read in a book that tension = 1/(pa'), where a' = alpha prime.

Is this the correct formula for string tension and if so what is p?

2. Feb 26, 2004

### lethe

in my book, it is

$$T=\frac{1}{2\pi\alpha'}$$

$\pi$ is the ratio of the circumference of a circle to its diameter, approximately 3.14. and if your source differs by a factor of 2 from mine, i wouldn't worry about it.

3. Feb 26, 2004

### ant0

ah, p must be pi then, would that make sense for a closed string then?