In the above video we study
reflections
of a wave in a cord with both ends fixed.
The video halts every time just before a new reflection
of the wave enters the cord:
1st pause:
Just before the first
reflection from the righthand side enters.
Notice here that the cord contains 3 complete cycles
and an additional 1/3 of a cycle
(3.33λ) of the incoming wave.
When the reflected wave moves to the left you may observe
standing waves occur because of its interference with the incoming wave.
The maximum amplitudes of the oscillatory movements are twice
the amplitude of the incoming wave.
2nd pause:
Just before the second
reflection from the lefthand side enters.
When the reflected wave moves to the right we observe
standing waves because of its interference with the incoming wave
and the reflected wave from the right.
But the maximum amplitudes of the oscillatory movements are NOT
three times as large as the amplitude of the incoming wave,
as one would expect.
3nd pause:
Continuation of the video at the next page.
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