Inertial Forces - Balls In Rotating Jars
To demonstrate inertial forces in bodies submerged in air and in water.
On one side of the arm a pingpong ball is suspended by a string from the top of a jar filled with air. On the opposite side of the arm a pingpong ball is attached by a string to the bottom of a jar filled with water. When the arm is rotated, the ball in the air jar moves outward and the ball in the water jar moves inward.
IRA 1D52.30) See Demonstration Reference File for several interesting articles.