Superposition and Interference Flashcards
What is superposition?
When two or more waves pass through each other, the displacements combine. The total displacement is the sum of individual displacements
What is constructive interference?
When the displacement of two waves is in the same direction, produces a bigger displacement
What is destructive interference?
When the displacement of two waves is in opposite directions, produces a smaller displacement
What does it mean if two points are in phase?
They are both at the same point in the wave cycle
What is phase difference (of a wave)?
The amount by which a wave lags behind another
What is a stationary wave?
The superposition of two progressive waves with the same frequency (or wavelength) and amplitude, moving in opposite directions. No energy is transmitted
What are the frequencies that stationary waves happen at called, and how many wavelengths fit on them?
Resonant frequencies, an exact number of half wavelengths fit on the string
What is a node?
A point on a wave with zero amplitude
What is an antinode?
Points of maximum amplitude
How many wavelengths fit onto the ath harmonic?
a/2
What is the resonant frequency of the ath harmonic?
frequency of the ath harmonic = a x first harmonic frequency
How does the length of the string affect the resonance frequency? Why?
The frequency would be lower the longer the length is, because of c = fλ. If the λ increase then f must decrease the fix c
How does the mass per unit length affect the resonance frequency?
The higher the mass per unit length the lower the resonance frequency
How does the tension affect the resonance frequency?
The lower the tension, the lower the resonance frequency
