Rotating Accelerometer - Physics Demonstrations - Rotating Accelerometer | Physics Undergraduate Labs

Keep hands, clothing, and loose items away from the rotating platform. The heavy platform has significant rotational inertia and can cause pinching injuries if fingers are caught between moving and stationary parts. Brief students to maintain distance during operation.

Purpose

Provides cognitive dissonance for students who expect all objects in a rotating system to be flung outward. An inverted water-filled flask with a fishing float is spun on a rotating platform; the float and air bubbles move inward toward the rotation axis, demonstrating buoyancy in a non-inertial reference frame.

Overhead view of inverted Erlenmeyer flask filled with water with orange fishing float visible inside, mounted in white aluminum frame on teal rotating platform with grid pattern

Side-angle overhead view of inverted Erlenmeyer flask with orange fishing float in white aluminum frame on teal rotating platform with grid markings

Figure 1: Overhead view of the inverted flask and fishing float mounted in the aluminum frame on the rotating platform. The float and air bubbles move inward when the platform spins.

Figure 2: The apparatus from a wider angle, showing the platform grid markings useful for tracking radial motion of the float.

2 L Erlenmeyer Flask with Water and Float

1

Safety Warnings

Warning: Rotating Platform Hazards

Purpose