i have to make a metal boat for science that will float and can carry a cargo of 50 pennies. Boat must be made of metal only. Support a cargo of 50 pennies for a minimum of 20 seconds.Fit within a 20cm. by 20 cm. square (can be no larger)
make the bottom rounded off
The only difference you'll notice is the sound.
On a turbocharged vehicle they help tons, not so much otherwise.
Since it needs to fit within a square and not a cube, make it SUPER tall so it will displace the most water and float better than everyone else's.
First you must calculate the weight of 50 pennies and the weight of the sheet of metal you choose to use. Then you should do a quick Buoyancy calculation (assuming you are floating on water): Buoyancy (Submerged Volume) x (Specific Weight of Water) where the specific weight of water is appx.: 9800 N/cubic meter. Next, do a force balance to ensure static equillibirum: Sum of Forces 0 Buoyancy - Weight 0 Therefore, you must calculate the weight of the sheet of metal and the 50 pennies. Weight (density of copper for pennies) * (9.81) * 50 * (volume of one penny) + (density of metal sheet) * (9.81) * (volume of metal sheet) on where 9.81 is the constant of gravitational acceleration. It may be lower or higher depending on where you live - but 9.81 is a fair estimate. The design challenge is then finding the correct geometry of the metal sheet to support the weight of the pennies and provide enough buoyancy to float. You may want to turn the sheet into a more round shape. You may have to optimally arrange your cargo to prolong the float time, as well. I hope this helps.
