In regards to a graph of the changing magnetic flux in a generator such as this one:
a) The equation of the graph should be $\Phi = BA \cos \theta$. As $\theta=\omega t$ (angular velocity*time), doesn't that mean the x axis should be wt, and not just time? (because a normal $\cos$ graph is $\cos(x)$, and this is $\cos(wt)$. Or am I misunderstanding cos wave equations?
b) How can the angular velocity/frequency of rotation be determined from this graph? Can $\omega = 2 \pi f$ be used? ($f=1/T$)