2.4a - Superposition

Define principle of superposition

when 2 or more waves travelling together through medium, resultant disturbance at any point is algebraic sum of individual disturbances

If two waves have same amplitude and are said to be in step, what does this mean?

in phase and we get constructive interference

If two waves have same amplitude and are said to be completely out of step, what does this mean?

out of phase and we get destructive interference

What is required for being in step/out of step and constructive/destructive interference and why?

two amplitudes equal, if unequal destructive interference takes place but resultant disturbance doesn’t equal 0

If waves said to be coherent, what does this mean?

produce waves of same wavelength and in phase/constant phase difference

Conditions of stationary waves

2 identical waves travelling in opposite directions

Frequency of stationary and progressive waves

particles vibrate with same frequency as wave

Stationary waves

no energy transfer

Define node

zero displacement