posted by pam .
AHHHHHH Help!! Mass on string of unknown length oscillates witha period of 6.0s What if string length is doubled? amplitude dbl?
Amplitude does not affect period if the oscillations are small (less than about 30 degrees).
If the approximation theta = sin theta is made, the period becomes
P = 2 pi sqrt(L/g)
What happens if you double L?
Period is sqrt2 times larger.
I don't think they expect you to know the exact formula for the period of a pendulum for large angle osciallations. It requires an infinite series. If you need to know it, and how to derive it, I can give you a reference.