# Forming Linear Equations From Non-Linear Equations

1. Nov 10, 2005

### K - Prime

For my first year formal lab im having a little bit of trouble with one aspect, lets see if anyone can help

Im trying to rearrange the equation

T = 2pi [(32 L I)/(pi S d^4)]^1/2

....(sorry, i dont know how to use the better way of displaying math) to form a linear equation so it can be graphed as a line, but im having a rough time of it. My biggest problem seems to be getting the + b segment (for the form y=mx+b), the + sign doesnt seem to want to show up when the origional equation is all multiplication. Any help would be appreciated.

2. Nov 10, 2005

### Fermat

Which are variables and which are constants.

The simplest way of linearising products of things to various powers is simply to take logs.

3. Nov 10, 2005

### K - Prime

Its an equation relating to a torsional pendulum with a metal disk at the end

I = moment of inertia for disk
L = length of suspending wire
S = shear modulus
d = diameter of suspending wire
T = period of rotation

the constants are S d and I

i think i need to graph T against L somehow
Ill give the log thing a shot

Last edited: Nov 10, 2005
4. Nov 10, 2005

### K - Prime

how does this sound, checking to see if im in the ball park

T^2 = {[4 pi (32) I]/(S d^4)} L

where T^2 = y L = x and everything in {} is m, guessing b doesnt apply here and any intercept on the graph can be attributed to error

Last edited: Nov 10, 2005
5. Nov 10, 2005

### whozum

That would work provided you don't change the parameters in the { }.