Governed by the waveequation. No losses. u_{tt} = c^{2}(u_{xx}+u_{yy}) for 0<x<l, 0<y<L u(0,y,t) = u(l,y,t) = u(x,o,t) = u(x,L,t) = 0 u(x,y,0) = f(x,y); u_{t}(x,y,0) = 0 f(x,y) = x(l-x)y(L-y) |
The same as above, but with f(x,y) = x(l-x)y(L-y)cos(2pix/l) |
The same as above, but with a different initial state, so that wave-propagation is easily seen. Note the inversion of the wave when reflected by the edge. |