Reference: M102
Category: Mechanics
Purpose: Demonstrates various principles of rotational motion.
Description: This is a large horizontal, rotatable turntable that can be spun by hand. Many experiments are possible with this apparatus:
1. Place two plastic cells of water on the turntable. One is flat (A) and the other is curved to fit the circumference (B). On spinning, the water in B stays flat, while in A the water assumes a parabolic form.
2. A vase of water with ping-pong balls suspended in it is placed on the turntable. When the table rotates, the ping-pong ball deflects towards the centre.
3. A ball can be placed at the centre of the rotating disc and tapped to initiate motion. Alternatively it can be loosely trapped with your fingers at about half the radius of the disc, and then released. The ball will move in circles. The frequency of the circular motion does not depend on either the radius or the mass of the ball, or on the radius of the orbit, but only on the frequency of the rotating disc.
4. To illustrate the Coriolis effect, start the platform rotating slowly then roll the ball across it. The ball will roll straight in the laboratory frame of reference but along a curved path in the rotating reference frame. The direction of curvature (left or right) depends on the direction of rotation of the platform (clockwise or counter-clockwise).
