# Derivation of angular frequency equation

1. Mar 21, 2012

### AToMic93

1. The problem statement, all variables and given/known data
Derive the angular frequency equation (ω=√(g/L) from following equations:

2. Relevant equations
1) ((d^2)*θ)/(d*t^2)= (-g/L)*θ
2) θ=θmaxcos(ωt+δ)

3. The attempt at a solution
I don't even know where to start

2. Mar 21, 2012

### Staff: Mentor

(1) tells you that $\frac{d^2\theta}{dt^2}$ is (-g/L)θ. (2) gives you a formula for θ. If you were only given (2), how would you find an expression for $\frac{d^2\theta}{dt^2}$ from it?

3. Mar 21, 2012

### AToMic93

Would you take the second derivative with respect to time? (giving d2/dt2) then set this equal to the other equation?

4. Mar 21, 2012

### Staff: Mentor

I suggest you give it a try

5. Mar 21, 2012

### AToMic93

So the main question I have then is for when I'm deriving how do I deal with the θmax? Do I treat it just like θ or do I treat it like a constant?

6. Mar 21, 2012

### Staff: Mentor

It is, of course, a constant. But do keep in mind that θ = θmaxcos(ωt + δ)

7. Mar 21, 2012

### AToMic93

Alright I got it. Thanks

Last edited: Mar 21, 2012