Guinea & Feather Apparatus

This classic Guinea and Feather Apparatus is designed to demonstrate that, in the absence of air resistance, all objects fall at the same rate regardless of mass — a key principle of Newtonian physics.

The apparatus consists of a 600 mm long, 38 mm diameter glass tube sealed with two rubber bungs. One bung is bored and fitted with an 8 mm side tube for connection to a vacuum pump, allowing the air inside the tube to be evacuated. When the air is removed, objects like a coin and feather fall at the same rate, illustrating Galileo’s principle of free fall.

Key Features:

• Clear glass tube: 600 mm long × 38 mm diameter
• Includes two rubber bungs – one bored and fitted with an 8 mm tube for vacuum connection
• Demonstrates free fall in a vacuum
• Ideal for senior physics demonstrations (NCEA Level 2 & 3)
• Compatible with standard laboratory vacuum pumps

Applications:

• Newton’s laws of motion
• Free fall and gravitational acceleration
• Air resistance vs. vacuum experiments

• Classroom demonstrations of classical mechanics