Each team will submit one self-propelled catapult, built by both members, to carry and launch a ping pong ball from a starting line to a given target. The device shall not exceed 40 cm by 40 cm dimensions. The length may be measured in either cocked or uncocked position. The energy sources shall consist of rubber bands or springs only. No other mechanical or chemical device may provide energy to either the movement of the apparatus or the propulsion of the ping pong ball.

The Competition: Each device will be placed behind a starting line. At the start signal, the student may release or otherwise activate the device without a push/pull start. No part of the device other than the wheels shall come in contact with any other object. The device must stop on its own. The device must carry the ball a minimum of 2 meters, but not more than 3 meters, before launching the ball. Lines will be marked on the floor indicating the 2 and 3 meter distances. A foul is declared if the  device does not reach the 2 meter line or if any part of the device exceeds the 3 meter line. A target will be marked on the floor 5 meters from the launch line (3 meter line). The distance measured radially from the center of the target to the point where the ball first contacts the floor, will be the launch distance. Each device will have an infinite number of trials. The grading rubric is as follows:

110% Lands and stays in bucket
105% Lands in but bounces out of bucket
100% Hits bucket
97% Under 0.5 meters
94% Under 1.0 meters
90% Under 1.5 meters
85% Under 2.0 meters
80% Legitimate Launch

1% added extra for each additional time you land and stay in the bucket!