[填空题]
A uniform narrow tube 1.80 xt/d;2httl7z/wrdp bhc; ,d) m long is open at both br/crdf;hg6 s y 23*dkends. It resonates at two successive harmonics of frequencies 275 Hz and 330 Hz. Wh32rbhfs6dy r k/dc ;g*at is
(a) the fundamental frequency, Hz
(b) the speed of sound in the gas in the tube?$\approx$ $ \times10^{2 }$ m/s
