[填空题]
(a) Determine the length kou +4uv+auqnvqe9) . ofa i6)h6cc *lv ;wjd5zxwnr ,arnt;x8 * an open organ pipe that emits middle C (262 Hz) when the temperature6)vh5nwi 8wz;,xndca j*larx*;r6 c t is 21 $^{\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