# Homework Help: Speed of sound/Dectecting insects

1. Aug 3, 2006

### FelicitaH

I've looked throughout my book for the formula, and I've looked online to see if there were similar problems so I could figure out how to do this, but I can't find anything.

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A bat can detect small objects, such as insects, whose size is approx. equal to one wavelength of the sound the bat makes. If bats emit a chirp at a freq. of 59 kHz, and if the speed of sound in air is 340m/s, what is the smallest insect (mm) a bat can detect?

Maybe it's easier than I think. I'm definitely not a physics person. I'm not asking for the answer, just some help in find the right equation :)

Thanks for any help.

2. Aug 3, 2006

3. Aug 3, 2006

### FelicitaH

Well. That's simple. I think the whole time I just wasn't reading "approximately equal to one wavelength.."

So, 340 m/s * 1,000 = 340,000 mm/s / 59 kHz = 5,762.

I've got to be doing something wrong/missing a step.

4. Aug 3, 2006

### Dmitri

Check the units.

5. Aug 3, 2006

### FelicitaH

Duh. Yes. Thank you!

5.763 :)

I feel stupid. Now that seems like a REALLY simple problem.