PURPOSE: To show the center of percussion. That is, to show the rotational reaction of a stick when it is struck by a puck at various points.
DESCRIPTION: A broomstick is placed on the floor. Using a lead weight, a puck is slid on the floor to strike the broomstick at various locations. The reaction from the stick to the point of impact by the puck is observed.
When the stick is struck below the center of percussion it will rotate away from the puck, in a direction opposite to the movement of the incoming puck.
When the stick is struck by the puck above the center of percussion it will rotate away from the puck, in the same direction as the incoming puck.
When the stick is struck at the center of percussion it will move away from the puck but it will not rotate, and reacts by moving in a straight line away from the puck.
EQUIPMENT: Stick, puck, as photographed.
Updated by Jun Qi in 3/24/2000