<span>We put a motion detector at </span>one end of the track<span> and put a cart on the track. ... Next, we put a motorized fan on the cart and let it push the cart down the track. ... This is what I would expect based on the velocity graph, since </span>acceleration<span> equals the slope of the velocity graph, which remains</span>constant<span> in time.</span>
I have a hunch that you're not talking about overtime
OR overtune. I think you're going for overtone .
For a fundamental frequency of 528 Hz,
1,056 Hz is the second harmonic.
