Courtesy of Louis S.:
The video I chose actually represents two aspects of physics in this
class. The set-up of the watermelon explosion is simply a large bank of
capacitors wired together in series with an extremely high voltage.
When one of the capacitors is discharged, there is an enormous current
that runs through the watermelon, causing it to explode. This shows the
relationship between capacitance, voltage, and current. The other
portion of this class can be seen with the high speed camera showing the
watermelon explode. When the watermelon is initially at rest, its
momentum is zero. Then, once it explodes, all of the little pieces of
watermelon-shrapnel must fly off such that the components of their
motion must equal zero.