# Acceleration of a pendulum

1. Nov 18, 2013

### Luke1121

1. The problem statement, all variables and given/known data
A pendulum has a length of 0.5m and an amplitude of oscillation of 8 degrees, what is maximum vertical acceleration

2. Relevant equations
$X=Acos(\omega t + \phi)$
$\omega =\frac{2\pi}{T}$
$T=2\pi \sqrt{\frac{l}{g}}$

3. The attempt at a solution
Taking the second derivative with respect to time for
$X=Acos(\omega t + \phi)$ then
$a=-\omega^2Acos(\omega t + \phi)$
$\omega$ can be obtained using $T=2\pi \sqrt{\frac{l}{g}}$ and doing $2\pi$ divided by this, but im unsure how to find $A$ Am I on the right lines? Thanks

2. Nov 18, 2013

### nasu

What is A in this formula?
Remember that you need vertical component of acceleration.