## ¿Frequency of ultrasounds to obtain oil drops in water?

1. The problem statement, all variables and given/known data

To obtain microemulsions of oil into water ultrasounds are used. ¿What is the frequency to obtain oil drops of 1 microgram wich density is 0.995 g/cm3? (It does not need to be exact, with only the order of magnitude is sufficient).

2. Relevant equations

Well, I don't know if it is a diffraction problem, or If I should use resonance , or stationary waves.

I am lost at this point, I don't know wich physical principles rely behind this process of creating microemulsions.

3. The attempt at a solution

I am very sorry, but I don't understand the process.

Any idea to solve this will be well received.

I know that in physicsforums you should put the equations in the point 2, but I don't know what is the exact process.

 I have had an idea, I now what is the mass of the drops of oil, and the density so: Volum=density/mass I suppose that the drops are spherical, so they have a volum of 4/3*pi*r^3. Finally I use: V=$$\lambda$$ / $$T$$ Where V is the speed of sound under water. $$\lambda$$ Is the wavelenght of the wave. $$T$$ is the period, or the inverse of the frequency. So, using V=1500 m/s and a size of 0.013 meters I obtain: Frequency $$\approx$$ 115384.6 Herzs So I suppose that the interference pattern of the emitted wave will create oil drops of the size of the wavelenght, logically it is an approximation, I only need to know the order of magnitude of the frequency. ¿Do you think that this is correct?.