Shoot & Drop

PIRA 1D60.20

Materials: Shoot and Drop Contraption, 2 Wood Blocks for height, 2 steel balls

Remove the pendulum and catch post from the (ancient) Cenco Ballistic Pendulum.  Besides the usual steel ball with hole that the device is designed to shoot, you need the brass ball with the larger hole that is designed to slip over the end of the shooting rod as shown above.  Elevate the device on some boxes or a stool over the edge of a table so that the brass ball will fall straight down to the floor and the steel ball will shoot over the table with an initial horizontal velocity.

When the device is triggered, the steel and brass balls will be released from the same height.  The steel ball will have a large initial horizontal velocity while the brass ball will have none.  Neither ball will have an initial vertical velocity.  Ask students which ball will hit the ground first, and have them listen for the two impacts.

Be sure to use a spirit level to ensure that the steel ball shoots horizontal.  If the floor has carpet, you will need to place identical thicknesses of plywood on the floor where the balls will strike.