The flask contains a saturated solution of excess sulfur in CS 2 . The crystallizing dish is half-filled with the solution, covered with a glass plate, and placed on the overhead projector. A particle...The flask contains a saturated solution of excess sulfur in CS 2 . The crystallizing dish is half-filled with the solution, covered with a glass plate, and placed on the overhead projector. A particle suspended in a fluid is constantly and randomly bombarded from all sides by molecules of the fluid, and this is noticeable, provided the particle is small and light enough (we do not, for example, notice the fluid of the atmosphere pushing around billiard balls).
The Langevin equation for the motion of a Brownian particle can be modified to account for an additional external force, in addition to the drag force and random force.
