Calculating Average Velocity of Colloidal Particles in Brownian Motion

In summary, the problem in question involves computing the average velocity of colloidal particles with a molecular weight of 3.2*10^6 g/mol, given the average speed of hydrogen molecules at 0 degrees C' is 1694 m/s. The formula for average speed is 1.59*sqrt(kT/m), where k is the Boltzmann constant. The principle of equipartition of energy is also relevant, with the equation 1/2kT=1/2mv^2 being used to solve the problem. The solution is 1.3 m/s, but the process of arriving at this answer is unclear.
  • #1
scarface223
2
0
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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  • #2
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?
 

What is Brownian Motion problem?

Brownian Motion problem, also known as the Brownian motion or the Wiener process, is a mathematical model describing the random movement of particles in a fluid. It was first observed by the botanist Robert Brown in 1827 and later explained by Albert Einstein in 1905.

How does Brownian Motion occur?

Brownian Motion occurs due to the constant collisions between the particles and the molecules of the fluid. These collisions cause the particles to move in a random, zigzag pattern. The smaller the particles, the more erratic the motion will be.

What is the significance of Brownian Motion problem in science?

Brownian Motion problem has significant implications in various fields of science, such as physics, chemistry, biology, and economics. It helps in understanding diffusion processes, predicting the behavior of microscopic particles, and developing models for various natural phenomena.

How is Brownian Motion problem related to the concept of entropy?

Brownian Motion problem is closely related to the concept of entropy, which is a measure of the disorder or randomness in a system. Brownian motion is an example of how entropy increases over time in a closed system, as the particles move to a more disordered state.

Can Brownian Motion problem be observed in real-life?

Yes, Brownian Motion can be observed in real-life through various experiments, such as the Brownian motion experiment using pollen grains in water. It is also visible in the movement of dust particles in a sunbeam and the diffusion of ink in water.

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