Sound coming out of slide whistle

[jai6638]

A slide whistle has a length of 27 cm. if you want ot play a note one octave higher the whistle should be how long?


Ans : 1/2 lambda = L

there Lambda = 2L
= (2)(27)
= 54 m

is that correct?

 

[Galileo]

That's a rather long whistle.
And the higher the frequency, the shorter the wavelength, so the whistle should be shorter if it's to produce a higher note.

 

[jai6638]

so it would be 27/2 = 13.5 m?

thanks

 

[Galileo]

13.5 m is also a tad long for a whistle. It'll look more like a digderidoo.
The length of the slide whistle was given in cm, not in meters.
I assume the whistle acts like a half open tube where waves have a node on the closed end and have a maximum at the open end, then the whistle should be half as long.

 

[HallsofIvy]

so it would be 27/2 = 13.5 m?

thanks

What, exactly, was the original length of the whistle? (Be Careful!)

 

[jai6638]

my bad.. so the answer is (.27)(2) = .54m?

 

[HallsofIvy]

Except that you are going the wrong way again: a longer wave length gives a lower frequency.

Since the original length was given as "27 cm.", I would be inclined to give the answer as 13.5 cm.