# Homework Help: Order of wavelength

1. Sep 14, 2016

### Deebu R

1. The problem statement, all variables and given/known data
Ultrasonic waves of frequency 3 x 10^5 Hz are passing through a medium where speed I found is 10 times that in air ( speed of sound in air is 300m/s). The wavelength of this wave in the medium will be in the order of?

2. Relevant equations
Wavelength = wave speed/ frequency.....maybe

3. The attempt at a solution
Using the equation I got 300 x 10/(3 x 10^5)=0.01

2. Sep 14, 2016

### BvU

Hi,

Is there a question you need help with here ?

I don't want to be corny, but: is that in inches, miles or in furlongs ?

3. Sep 14, 2016

### Deebu R

I am guessing meters so in cm it becomes 1 cm, right?

4. Sep 14, 2016

### BvU

Of course. It's just that I wanted to emphasize to you that you should always include units.

(also in calculations: 300 m/s x 10/(3 x 10^5 /s ) = 0.01 m -- the factor 10 is a ratio, no dimension)

5. Sep 14, 2016

### Deebu R

I was just making sure. Thank you for the help.