Document Type

Article

Publication Date

6-2003

Publication Title

American Journal of Physics

Keywords

Physical Constants, BrownianMotion Processes, Polystyrene, Video Microscopy, USM

Abstract

Boltzmann's constant k was measured by observing the Brownian motion of polystyrene spheres in water. An inexpensive monochrome CCD camera and video card were used to create a video of the spheres' motion. After preprocessing the images, custom routines were used to examine the video and to identify and track the particles from one frame to the next. From the mean squared displacement of the particles versus time, we extracted the value of k from the slope, assuming that the drag force on an individual sphere is well modeled by Stokes' law.

Comments

Copyright of American Journal of Physics is the property of American Association of Physics Teachers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.

http://dx.doi.org/10.1119/1.1542619 http://ajp.aapt.org/

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