[填空题]
An unfingered guitar string iiynk6; 4/ d;4cw;wbg6 qo wfscs 0.73 m long and is tuw 1s3. .iomm9osefa i;ned to play E above middle C ( awmiofo9 .1m;esi s.3330 Hz).
(a) How far from the end of this string must the finger be placed to play A above middle C (440 Hz)?$\approx$ m
(b) What is the wavelength on the string of this 440-Hz wave? $\approx$ m
(c) What are the frequency and wavelength of the sound wave produced in air at 20°C by this fingered string? Hz m
