[填空题]
A uniform narrow tube 1.80 m long is open at bot3nf e-,pthjmni :yt;g 04ez( .da+fh th ends. It resonat idkpa (inb*w63k 6by :rcxrwvw51 49mes at two successive harmonics of frequencies 275 Hz and 330 H(ky56 v1cnd6xib4r:wir* a3 wbwkm9 pz. What is
(a) the fundamental frequency, Hz
(b) the speed of sound in the gas in the tube?$\approx$ $ \times10^{2 }$ m/s