1M40.62 Basketball Cannon

Mechanics» Work and Energy» Conservation of Energy

Prime the cannon by firing once before demonstrating. Unlock the propane torch trigger by rotating the trigger button counterclockwise; adjust the flow rate. Using the mister as a fuel injector, pump the mister until a fine ethanol mist is produced, then tilt the cannon away from vertical, hold the mister just inside the mouth of the cannon, and pump firmly nine times at the bottom of the cannon. Inside the cannon, 12 centimeters below the mouth, is a ring to support the basketball; press the basketball into the ring just far enough that it is not loose. CAUTION: Squeezing the basketball into the cannon any tighter causes excessive pressure inside the cannon during ignition. Place the torch nozzle just inside the 1.5-centimeter opening near the bottom of the cannon and turn on the torch to fire the cannon. The cannon can bounce the basketball off the seven-meter-high lecture hall ceiling.

Comments

Besides conversion of ethanol and oxygen chemical potential energy into kinetic energy, the cannon can also be used to demonstrate trajectories. "C - Clamp" the wood cannon base to the adjustable slide projector tilt table, G2B20A, to control the initial firing angle for the cannon. To increase the range of the cannon, the basketball diameter can be adjusted using compressed air with a needle adapter, G2B20A, to leave a gap as small as desired between the ball and the inner wall of the cannon. The basketball diameter can be adjusted over a range of about 1.5 centimeters. A cannon constructed from 10-inch cardboard concrete form tube, 1A, can be used instead of the PVC cannon.

Apparatus

10-inch ID, 0.25-inch-thick walls PVC Cannon

Basketball

water mister

100% ethanol

propane torch with piezoelectric trigger