Calculating Average Velocity of Colloidal Particles in Brownian Motion

scarface223
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In one of my homework problems it is a problem under the section of Brownian motion. It asks me to compute the average velocity of particles!

here is the exact problem:

The average speed of hydrogen molecules at 0 degrees C' is 1694 m/s. Compute the average speed of colloidal particles of "molecular weight" 3.2*10^6 g/mol.

-What I know about the problem is that the formula for avrg speed is 1.59*sqrt(kT/m), where k is the Boltzmann constant! I do not understand why so much information is given? How can I convert molecular weight into simple mass? The ans is also 1.3 m/s, but i have no idea how to arrive at it, please help! I would show more work, but I am not really getting anywhere so far
 
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The equipartition of energy principle requires that the KE when there is Brownian motion is 1/2kT. So if I set up the equation such that 1/2kT=1/2mv^2, am i on the right track?
 
To solve this, I first used the units to work out that a= m* a/m, i.e. t=z/λ. This would allow you to determine the time duration within an interval section by section and then add this to the previous ones to obtain the age of the respective layer. However, this would require a constant thickness per year for each interval. However, since this is most likely not the case, my next consideration was that the age must be the integral of a 1/λ(z) function, which I cannot model.
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