[填空题]
(a) Determine the lengthiwd3 7j(1,q4 piyowtg of an open organ pipe thavtt3idl.w2b -pfbs :/t emits middle C (262 Hz) when the temperature is 21pb w:svd2. t/3btfi-l $^{\circ} $ C. m
(b) What are the wavelength and frequency of the fundamental standing wave in the tube? Hz m
(c) What are $\lambda$ and $f$in the traveling sound wave produced in the outside air? Hz m