Physics 312 Lecture: "Superposition of Waves and Standing Waves I."
Apr 10, 1998
- When two sinusoidal waves with identical frequencies and
wavelengths interfere, the result is another wave with
the same frequency and wavelength, but a maximum amplitude
which depends on the phase difference between the input waves.
- Constructive interference occurs when the phase difference
between two waves is zero, or some multiple of pi radians
- Destructive interference occurs when the phase difference
between two waves is some multiple of pi/2 radians
- Adding two sound waves which are out of phase may yield silence!
- Standing waves occur when a wave reflects back and forth in
a confined space and interferes with itself
- Nodes are locations where a standing wave has zero amplitude
- Antinodes are locations where a standing wave has maximum amplitude
- Waves travelling on a string fixed at both ends are constrained
to have specific wavelengths and frequencies
This lecture discusses material in Chapter 18 of Serway.
