**Objectives:**

- To build a "boat" or "raft" out of plastic materials that is capable of holding four people.
- To build a "boat" or "raft" out of plastic materials that is capable of being launched and propelled across a pool
- To apply Archimedes' Principle to the design.

**Materials:**

- Only plastic materials can be used.
- The maximum thickness of the plastic materials cannot exceed 1/4 inch.
- Only the approved tape (cheap, clear postal tape that is about two inches in width) and nylon twine can be used.
- Four paddles will be provided.

**Design Parameters:**

Boats will be subject to a technical inspection and must follow these guidelines:

- Boats must be made from plastic. Any form of plastic is acceptable as long as the thickness of the plastic does
**not**exceed 1/4 inch. - The maximum length is six feet.
- The maximum width is five feet.
- There is no restriction on thickness, as long as it does not exceed five feet (and would therefore be considered as a length or width dimension).
- Only the approved form of tape and nylon twine can be used.
- You may not use any other materials other than the approved tape and nylon twine for attaching parts of your boats. No glue may be used. No "melting" of plastic may be done.
- The boat may
**not**be wrapped in plastic, duct tape, shrink-wrap, or anything else. Only the seams and joints can be taped, not the entire boat. - No appendages or any other part of your passengers may be in the water. No arms or legs may be in the water to assist with stability or propulsion. No part of any passenger may be touching the water.
- To qualify as a finisher, all teammates must be in the boat at the end of the race.
- You will work in lab groups of four per team.
- Extra credit will be awarded for a theme.
- A theme can consist of coordinating clothes, hats, etc.
- A theme can consist of decorations on your boat. All decorations must be made of plastic and be affixed to the boat with approved tape or nylon twine. Only markers can be used (no paint,etc.)
- The content of the theme must be appropriate, following the rules described in the student handbook.

- You may arrange to have two friends assist you at the starting line while you "load" your boat.
- A shoreline start will be used. As soon as the whistle blows, you may begin to "load" your boat. As soon as all team members are in the boat, you may begin to paddle across the pool.

**Grading Guidelines:**

- The plastic boat project will have the same weight as a test grade. It will consist of a total of 100 points, 20 points allotted for the group grade and 80 points allotted for the individual student report.
- Group grade:
- Any boat that successfully clears the starting line will earn 12 points.
- Any boat that successfully negotiates 1/4 of the pool's width will earn an additional two points for a total of 14 points.
- Any boat that successfully negotiates 1/2 of the pool's width will earn an additional four points for a total of 16 points.
- Any boat that successfully negotiates 3/4 of the pool's width will earn an additional six points for a total of 18 points.
- Any boat that successfully negotiates the entire pool's width will an earn an additional eight points for a total of 20 points.

- Individual student report:
- Scale drawing of the design (10 points). You must include a scale for your drawing. Please label all dimensions. Include a "top" and a "side" view.
- Data table (20 points):
- List components of boat with their masses individually. If the weight of the components was known and you converted to kilograms, show this conversion. Give the total mass of the boat.
- List mass of contents individually (passengers, decorations, paddles, etc.). If the weight of the contents was known and you converted to kilograms, show this conversion.
- Total mass of contents.
- An estimate of depth of boat loaded with contents. In other words, your boat is twelve inches thick; a passenger estimated that it sunk into the water three quarters of the way at the pont. You would record this estimate as nine inches. Try to take your estimate at a corner. All team members should be responsible for making this estimate when "loaded" on the boat. Remember both to look and remember this estimate. Include a drawing with your report showing the estimated depth at each corner (since the masses of your contents vary, the depths at each corner should also vary).

- Calculations (40 points): Show
**all**work! Remember to use SI units. 5 points each, except for number one which is worth 10 points.- Calculate the volume of water displaced by the boat and its contents.
- Knowing the volume of water displaced, calculate the buoyant force exerted by the water on the boat.
- Calculate the total mass of the boat and its contents.
- Calculate the total weight of the boat and its contents.
- Compare the weight of the boat and its contents to the buoyant force using a percentage error calculation. Let the total weight of the boat and its contents represent the "actual" value and the calculated buoyant force represent the "experimental" value.
- What should be the relationship between the buoyant force and the weight of the boat and its contents?
- Do your results support this relationship? (A yes or no answer does not suffice.)

- How would you improve your design to make it more "sea-worthy" (ten points)?

**Student Records:**Rank Team Members Time in seconds Year Set 1 Nick P., Curtis P., & Joe V. 28.07 2004 2 Donnie M., Tara F., Kirsten K., & Casey S. 29.13 2004 3 Susan K., Chris J., & Whitney H. 29.60 2004 4 Daniella F., Jenni B., Kendall H., & Rob P. 31.29 2004 5 Shannon G., Eduardo G., Jeremy R., & Javier B. 36.63 2001 6 Aaron B., Tim B., Eric S., & Matt L. 37.38 2001 7 Katherine B., Erin C., Tom S., & Michelle T. 40.00 2004 8 Ashley A., Melissa H., Daniel K., & Jeff R. 40.25 2001 9 Rami H., Nick McC., Jon M., & Lindsey A. 41.50 2002 10 Jason V., Amy F., Nara K., & Preston M. 45.96 2004