VCAA 2007 Question 5 D sound detailed area of study.

[rk]

VCAA 2007 Question 5 D sound detailed area of study.
Do you know how to do it?

[Chavi]

With pipes closed at one end, each corresponding resonant frequency is 3 times the first (fundamental) frequency.

For open-closed tubes, the first resonance is at L=λ/4, so λ=4L=2m. Hence, f=170 Hz.
Then just times this by 3 to get 510hz (i.e. D)

[3Xamz]

Not to hijack this thread, but what would have to those frequencies inbetween the resonant frequencies?
would we hear a muffled sound or what's up?

[Chavi]

Not to hijack this thread, but what would have to those frequencies inbetween the resonant frequencies?
would we hear a muffled sound or what's up?

You still can hear it. It just doesn't resonate (i.e. produce a standing wave).
It really depends on the situation - for example, if you're blowing into a flute with the wrong frequency, nothing will come out - so professional flutists are trained to hit those notes by matching the forcing frequency of their breath to the natural frequency of the flute. . .

[3Xamz]

So you can still hear it even though its not resonating?
How can you differentiate between a resonating sound and a ..non-resonating sound?

Assuming both sounds are produced inside identical tubes.

[Chavi]

So you can still hear it even though its not resonating?
How can you differentiate between a resonating sound and a ..non-resonating sound?

Assuming both sounds are produced inside identical tubes.

In real life, you'll just hear an unnaturally louder sound. For the purposes of VCE physics, you just have to know that Resonance is the superposition of a wave and the reflected wave to produce standing waves (containing nodes and antinodes). This occurs when the forcing freq equals the natural freq of the object.