In this lab we will investigate the buoyant force on a 36 in² piece of aluminum foil  Our method will be to build a foil barge and determine the maximum number of pennies it can hold without sinking.

 

 

First, fold your 6 inch x 6 inch piece of aluminum foil into a rectangular "barge." As you fold, be very careful not to rip the foil, making all of the "walls" the same height, and sealing all of the corners..

 

image courtesy of TeaWithBuzz

 

Once the barge has been constructed, measure in centimeters the length and width of its base and the height of its walls to one decimal place. 

 

 

Next you need to determine the average mass of a single penny so that you can predict the maximum number of pennies that can be placed in your barge without it sinking.

 

 

Count out your predicted number of pennies and carefully place your barge in the water tub. Make sure that the barge has NO contact with the walls of the tub or its base.

 

 

Slowly begin placing your pennies. Remember to keep the barge balanced and the pennies symmetrical. Keep going until you feel that no more pennies can be safely added to the barge. If you have exceeded your predicted number, you may get additional pennies.

 

Once you stop adding pennies, your barge must float for a minimum of 60 seconds. If the barge sinks on the 59th second, it is disqualified, the same as if it sank on any earlier second. After you have completed your timing, you may NOT add any additional pennies.

 

Remove your barge from the water tub and set your pennies out to dry.