Undergraduate experiment on Brownian motion using video microscopy

Abstract

This paper presents measurement of Boltzmann's constant by observing Brownian motion of polystyrene beads suspended in water. The measured value of the Boltzmann's constant is k = (1.49 ± 0.14) x 10^-23 J/K which has percent error of 7.65% as compared to the accepted value (k =1.38 x 10^-23 J/K). We also present method of doing video microscopy designed for an undergraduate laboratory.