Questions/Comments on Waves and Interference
Tue, Mar 18, 11:00 a.m. - how do i determine the delta phi from a wave diagram so that i can use it in my phasor diagram?
I presume you're referring to plots of two waves or oscillators and you're asked to find the phase difference $\Delta\phi$ between them. Here's the technique:
First, figure out the wavelength or the period. Pick either one of the waves, find two peaks, and measure the difference between them.
Second, figure out the shift between the two waves. I.e., how much is wave 1 shifted relative to wave 2.
Then the phase difference is $2\pi \times (\hbox{shift}) / (\text{period or wavelength})$. I.e., what fraction of the wavelength is the shift? If it's half a wavelength, then $\Delta\phi = 2\pi \times 1/2 = \pi$. If it's a quarter of the wavelength, then $\Delta\phi = 2\pi \times 1/4 = \pi/2$.