[填空题]
(a) Determine the length of an opa s.hr eer6bk62s tm60en organ pipe that emits middle C (262 Hzv*w33 n4jq rh6tb mf-u) when the temperature is 21q4-fn 3utb rvhj*m3 6w $^{\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