- #1

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My answer is not identical to what in my text book.

My thought is :there is no change of the wavelength, as the time given is enough for the wave to move over one wavelength.

- Thread starter primarygun
- Start date

- #1

- 232

- 0

My answer is not identical to what in my text book.

My thought is :there is no change of the wavelength, as the time given is enough for the wave to move over one wavelength.

- #2

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anyone helps?" Need to help my friend

- #3

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are you sure the problem requests the change in apparentprimarygun said:

My answer is not identical to what in my text book.

My thought is :there is no change of the wavelength, as the time given is enough for the wave to move over one wavelength.

btw, what answer does the textbook give?

- #4

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It is the observed wavelength and the answer is 0.75 cm, half of the wavelength.

- #5

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from the stated problem, it seems you'd perceive an apparent change inprimarygun said:

My answer is not identical to what in my text book.

My thought is :there is no change of the wavelength, as the time given is enough for the wave to move over one wavelength.

on the other hand, the frequency would appear to change. because the strobe frequency of 6 Hz is not aligned (or "synced") with the wave frequency of 8 Hz, the viewer would only see a wave peak return to a given position every 1/2 second (= 3 strobes @ 6 Hz = 4 wave cycles @ 8 Hz). that's the shortest elapsed time for which the 6 Hz strobe can coincide with the 8 Hz wave's peak returning to a given position:

Code:

```
strobe wave peak @ given position
(sec) (sec)
0 ** ** 0
1/6 1/8
2/6 2/8
... 3/8
3/6 ** ** 4/8 ---- wave period would appear to be 1/2 sec
```

thus, problem answer seems to be:

wave

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