A 50 cm long hollow glass cylinder is open at both ends and is suspended in air. A source of sounds that produces a pure frequency is placed close to one end of the tube. The frequency is placed close to one end of the tube. The frequency of the sound source is slowly increased from a very low value. The tube is first observed to resonate when the source frequency is 320Hz.
(I) The speed of the sound in the tube must be:
(II) The frequency of the source is slowly increased until resonance occurs again FOR THE THIRD TIME. The frequency at which this happens is:
(III)The frequency when resonance occurs for the FIFTH time is: