Molecular Motion Model - Physics Demonstrations - Molecular Motion Model | Physics Undergraduate Labs

Purpose

A vibrating frame on an overhead projector drives steel ball bearings to model molecular motion. Students see how temperature (motor speed), pressure (wall collisions), and volume relationships emerge from microscopic particle behavior. Multiple configurations demonstrate diffusion, Boltzmann distributions, and gas law relationships.

Molecular motion demonstrator kit laid out: blue vibrating frame with motor, white wooden energy level frame, plexiglass piston, glass evaporating dish with colored spheres, containers of steel ball bearings in various sizes, wooden spacer, and barriers

Figure 1: Complete molecular motion demonstrator kit: vibrating frame with motor, energy level frame, plexiglass piston, glass evaporating dish, assorted spheres and ball bearings, barriers, and spacer for tilting.