Suppose you blow the top of a bottle and hear a resonance sound (standing wave). The length of the bottle is about 25cm. If the speed of sound in air is about 340 cm/sec., what is the frequency of the sound you hear? Draw a diagram to show the standing wave in the bottle.
Speed = frequency .wavelength
Frequency = speed/wavelength
Speed = 340 m/sec length = 25cm
Wavelength can be determined by knowing the length and the number of harmonics.Here,we take first harmonic which would be four times the length ,so
Wavelength = number of harmonics X L
Frequency = speed/wavelength