Calculating Average Velocity of Colloidal Particles in Brownian Motion

Click For Summary
SUMMARY

The discussion focuses on calculating the average velocity of colloidal particles in Brownian motion using the formula for average speed, which is 1.59*sqrt(kT/m). The problem specifically involves hydrogen molecules at 0 degrees Celsius with an average speed of 1694 m/s and colloidal particles with a molecular weight of 3.2*10^6 g/mol. The correct average speed for the colloidal particles is determined to be 1.3 m/s, achieved by converting molecular weight into mass and applying the equipartition of energy principle.

PREREQUISITES
  • Understanding of Brownian motion principles
  • Familiarity with the Boltzmann constant (k)
  • Knowledge of molecular weight conversion to mass
  • Basic grasp of kinetic energy equations
NEXT STEPS
  • Study the Boltzmann constant and its applications in statistical mechanics
  • Learn about the equipartition theorem and its implications in thermodynamics
  • Explore molecular weight conversion techniques for different substances
  • Investigate the relationship between temperature and particle velocity in gases
USEFUL FOR

This discussion is beneficial for physics students, researchers in thermodynamics, and anyone interested in the dynamics of colloidal particles and Brownian motion calculations.

scarface223
Messages
2
Reaction score
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
 
Last edited:
Physics news on Phys.org
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?
 

Similar threads

  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 4 ·
Replies
4
Views
4K
Replies
3
Views
1K
  • · Replies 32 ·
2
Replies
32
Views
3K
  • · Replies 7 ·
Replies
7
Views
1K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 9 ·
Replies
9
Views
1K
Replies
5
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
3K