yes, Calculus *is* awesome. So is Physics.

This applies to the pendulum swing too doesn't it? The velocity of the bob is greatest at the mid point of the swing and is least at it's peak hight.
The cool thing is that the bob has the same amount of energy no mater where it is, it's just all potential energy at the peak hight and all kinetic energy at the equilibrium position and a combination of the two anywhere in between.