Why Doesn't the Drop Height Affect the Pendulum's Period?

[student34]

Homework Statement

What's the period to a 1 meter long physical pendulum string where L = 1M
T=2∏√((2L)/(3g)) = 1.64s

But, I did my own experiment, and the higher I dropped the pendulum the longer it took for it to travel 1 oscillation. What is going on here?

Homework Equations

The Attempt at a Solution

 

[TSny]

Hi student34. The formula that you are using is only an approximate formula. It's pretty accurate for small amplitude oscillations (the smaller the better), but becomes more and more inaccurate as the amplitude is increased. See http://en.wikipedia.org/wiki/Pendulum

 

[student34]

Hi student34. The formula that you are using is only an approximate formula. It's pretty accurate for small amplitude oscillations (the smaller the better), but becomes more and more inaccurate as the amplitude is increased. See http://en.wikipedia.org/wiki/Pendulum

Thank you so much. I thought I was going crazy!