The information below is subject to change as more event tips and details are included.  Please monitor this page regularly.

Event Description:

Teams of two to three students select from random a submarine from those provided before the trials. The submarine consists of a hollow plastic tube 4 to 8 inches long, about 1.5 in. in diameter, with stoppers on each end. The students must calculate the amount and optimal type of ballast needed to achieve neutral buoyancy (or a just bit more ballast) such that the submarine will suspend for significant time under the surface of the water tank provided (a large aquarium or similar).  Points toward the final score are awarded (1) for a quiz and (2) for the maximum time the submarine is suspended before any part touches the bottom of the tank (in three trials). The quiz, calculations, selection of ballast (amount and type: washers or rods), the assembly and loading of the submarine in the tank have to be performed within specified time limits determined by the judges.

Event Location and Time:

Apparatus and Materials:

Each team will be provided the following before the quiz and event trials:

• 2 sheets of standard copy paper, 11" by 8½" (Letter Size)
•  Scientific calculator
•  Electronic balance
•  Ruler and calipers

The materials provided in assembly of the submarine :

• set of plastic tubes about 1.5 inch diameter by 4 to 8 inches long (one chosen at random) with stoppers of same diameter  at each end.
• ¼ inch. diameter  washers as one possible choice of ballast
•  set of copper rods  as one possible choice of ballast

Event Rules:

Teams:  Each team shall have no less than two and no more than three members.
Quiz: Prior to the start of the competition each team will take a written quiz worth 30% of the total score. The time allotted for the quiz is 10 minutes. Quiz primarily will cover Archimede's principle of buoyancy.
Assembly: Only the components provided before the event trials are permissible in assembling  the submarine and for use as ballast.
Loading:  The submarine will be loaded with the appropriate amount and type of ballast  before each  trial. 
Trials: If the submarine floats after release with any part above the surface, no points will be awarded for that trial. Each group will have two additional attempts to change the original ballast as needed to maximize the time the sub is suspended before any part of the sub touches the bottom of the water tank, which is about 2 feet deep.  (An electronic scale will be provided)
Ballast: The ballast  provided are standard 1/4" washers and copper rods of various weights. The students must select the optimal type of ballast ( or combination ) to be used  for the longest , stable suspend time.
 Sink: The time from the point of release in the water (with the sub just submerged )  to the time any part hits the bottom  will be recorded and the longest time among the three trials used in calculating the points awarded. 

Judging Criteria:

Total Score:  The total score will be determined as follows:
    Total Score = (Quiz score,5pts maximum x 0.30) + (Best suspend time )

(Ties: If there is a tie, the second best time from each group will used. Should a tie still exist, the team with the higher quiz score shall be declared winner. If one or more teams are still tied after this, they shall share first place.)

Gold, silver and bronze medals will be awarded to the teams with the highest three scores, respectively. 

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Revised: March 08, 2008.