A room has two opposing walls which are tiled. The remainingwalls, floor, and ceiling are lined with sound-absorbent material. The lowest frequency for which the room is acoustically resonant is50Hz.
a) A complex noise occurs in the room which excites only thelowest two modes, in such a way that each mode has its max.amplitude at t = 0. Sketch the appearance, for each mode seperatly,of the displacement versus x at t = 0, t = 1/200 sec, and t = 1/100sec.
b) It is observed that the max. displacement of dust particlesin the air(which does not necessarily occur at the same time ateach position!) at various points between walls is asfollows: x L/4 L/2 3L/4 ? max +10? +10? -10? What are the amplitudes of each the two seperate modes?