Summary
Highlights
The video introduces an example with two pulses: one with a height of 10 units traveling right, and another with a height of 4 units traveling left. The first question is whether this will be constructive or destructive interference.
When both pulses are on the same side of the equilibrium line (both above, in this case), it's constructive interference. If one was above and one below, it would be destructive.
During constructive interference, the superposition principle states that the amplitudes add up. So, 10 units + 4 units results in a combined pulse of 14 units high.
After interference, the pulses pass through each other and return to their original heights and directions. The 4-unit pulse continues moving left, and the 10-unit pulse continues moving right.
A new example is presented for destructive interference: a pulse of 7 units moving right and a negative 2 units (meaning below the equilibrium) moving left. Destructive interference means the waves will 'break each other down'.
During destructive interference, the amplitudes are added. For this example, 7 + (-2) = 5 units. The combined pulse will have a height of 5 units.
After destructive interference, the pulses return to their original heights and directions. The 7-unit pulse (above) continues to the right, and the negative 2-unit pulse (below) continues to the left.