A teacher stands well back from an outside doorway that is 95 cm wide and blows a frequency of 600 Hz. The door faces north. Assume the speed of sound is 340 m/s and that there are no reflections. At ...
I know about and believe to understand the general wave equation based Kirchhoff diffraction formula, which in the Fraunhofer limit leads to a farfield complex wave function by Fourier transforming ...
Hold two cards (say credit cards) edge to edge, anything from a very slight touch to about 1/3 mm separation, in front of any ordinary light source. When I do this I see several fine dark parallel ...