Question

A closed pipe of length 50cm has water at 40cm. After been struck with a frequency of 256Hz, the water level moves up to 45 cm. What is the wavelength?

Answer 1

The wavelength of sound is 20 cm

The open end of pipe is truck with frequency = 256

The water level is at the distance =  45 cm

Thus the distance of open end from water level = 50 - 45 = 5 cm

The resonance is produced at a distance of λ/4

where λ is the wavelength of sound

Thus the distance of open end = λ/4

or wavelength λ = 4 x 5 = 20 cm