40. Simple Accelerometer

This device consists of a tethered ball floating in a jar of glycerin. To establish its operation, hold it in front of you, and begin rapidly walking across the lecture hall. The ball will move forward in the direction of your acceleration at first, and then return to the vertical position as your velocity becomes constant. When you stop walking, the ball will move back towards you showing a deceleration.

Now that you have demonstrated that the ball moves in the direction of acceleration, place the device on a turntable and start it rotating. The ball will move inward showing the radially inward uniform circular acceleration.