physics. HELP PLEASE
posted by chelsea .
One method for measuring the speed of sound uses standing waves. A cylindrical tube is open at both ends, and one end admits sound from a tuning fork. A movable plunger is inserted into the other end at a distance L from the end of the tube where the tuning fork is. For a fixed frequency, the plunger is moved until the smallest value of L is measured that allows a standing wave to be formed. Suppose that the tuning fork produces a 449-Hz tone, and that the smallest value observed for L is 0.202 m. What is the speed of sound in the gas in the tube?
The open end is antinode for the standing wave in air column, the closed end (plunger) is nod, => L= λ/4 => λ = 4•L.
4•L = v/f.
v = 4•L• f =4v0.202•449 =362.8 m/s