The Logic Off Topic list

At 12:03 PM 15/10/01 -0400, Debbie wrote:

>Calculate out freq. of each tone generator and the resultant wavelength of 
>each sound wave at room temp.
>
>A is 10ms
>B is 0.1ms
>
>No. 1 ms = 1 millisec which is one thousandth of a second = 0.001 second 
>and 10ms is 0.010ms how do i do the rest.
>
>Sorry had bad weekend with dad and had to move out and every thing, and i 
>just can't seem to think.

Sorry to hear you're having a rough time Debbie. Hope things work out for
you and soon.


>c = sound  f = freq. /\ = wavelength
>
>a)   Calculate the output freq.and wavelength for each one. 10ms = 0.010ms f 
>= 1/t = 1 divided by 0.010 = 100Hz
>
>b)  0.1ms = 0.001ms f = 1/t = 1 divided by 0.001ms = 100hz
>
>Is this right Murray?

0.1 ms is one ten-thousandth of a second 

f = 1/t = 10,000 Hz or 10kHz for the wave with a period of 0.1 second

>The question was two generators a + b are fed to both an oscilloscope and a 
>loudspeaker via a switch box enabling each to be viewed and heard either 
>separately or combined.
>
>period of output a is 10ms
>
>period of output b is 0.1ms
>
>Calculate the output freq. for each tone generator and the resultant 
>wavelength of each sound wave at room temp.

OK -- well you already know the two frequencies 100hz and 10kHz.

Wavelength = velocity/frequency

using your symbols from above that can be expressed

^= c/f

c = speed of sound = 340 metres/second

so for 100Hz wave

^ = 340/100 = 3.4 metres

For 10kHz wave

^= 340/10,000 = 0.34 metres

BTW I actually did these calculations in the email I sent last week  --
might be worth another look. I went on to talk about the different
properties of these two waves.

Hope this helps a little,
Murray