IB Physics Standing Waves Flippingphysics by Nothingnerdy
presentsa production Standing Waves 1 Image: Chladni design
Superposition The displacements of two waves travelling at the plus same place add vectorially to produce a resultant. equals What will be the resultant when the waves have each travelled 1/4 of a wavelength further?
Waves in 1D Wave from left Standing wave Wave from right where they cross The black dotted line shows the vector addition ofthe red and blue waves. Identify the positions where displacement is max and where it is zero.
Waves on a string fundamental modeN A N f = v/2L Distance LN A N A N 2nd harmonic f = v/L 3rd harmonicN A N A N A N f = 3v/2L N = node, A = antinode,position of zero position of max. Draw the next amplitude amplitude 2 modes
Waves in a pipefundamental modeN Distance L A f = v/4L 3rd harmonicN A N A f = 3v/4L 5th harmonicN A N A N A f = 5v/4L Here, the node is a position of zero Draw the nextamplitude but also maximum pressure 2 modes
Amplitude and phase For this standing wave on a string, each point has a different amplitude to its neighbour. All the points between two adjacent nodes are in phase with each other. The points on the left side are π rad out of phase with the points on the right side.
Standing vs travelling Standing wave Travelling wave The wave shape The wave shape doesn’t move progresses Neighbouring points Neighbouring points have different amplitudes have the same amplitude Neighbouring points Neighbouring points have the same phase have different phase It stores energy It transmits energy
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