Homework Help: Is this Wavelength answer correct?

1. Sep 16, 2007

onrytxn

The question is: Calculate the wavelength of a 1.5 MHz sound wave that is being transmitted through soft tissue. (This is Ultrasound physics, if you are wondering.)
formula used: wavelength = velocity (1540 m/s) divided by 1.5 MHz

MHz changes to 1.5 x 10^6

so I have: 1540m/s / 1.5 x 10^6 1/s=10.27 x 10^-4m or 10.27mm

Is this correct? I'm worried about my conversion---I tend to mess up the most simple conversions.

Thx!

Kathy

2. Sep 16, 2007

Astronuc

Staff Emeritus
10.27 x 10-4m is correct, however it is not 10.27 mm (which is ~0.4 inch).

Ultrasound has short wavelengths, usually < 1 mm.

So 1 mm is 10-3 m.

10.27 x 10-4m = 1.027 x 10-3m = 1.027 mm, which is long for UT.

3. Sep 16, 2007

onrytxn

Thank you! Those darned old decimals get me every time!!!!