Foil Boat Challenge
Purpose: To demonstrate buoyancy, Archimedes’ principle and density
Background Information: Boats float because there is a greater force pushing up on the ship than the
weight – or force – of the boat Buoyancy is the ability of a fluid to exert an upward force on an object
immersed in it. If the buoyant force is equal to the force exerted by the object, it will float. If the buoyant
force is less then the object will sink. Archimedes’ discovered that the buoyant force on an object is equal
to the weight of the fluid displaced by the object.
Materials:


2 pieces of Aluminum Foil
(15 cm x 15 cm)
Water

marbles

Paper towels

Bowl

Digital Scale
Procedures
Part 1
1. Measure and cut two pieces of aluminum foil. They should be 15 cm by 15 cm.
2. Take one piece of foil and crumple it into a tight ball. Weigh this ball of aluminum foil
Record in your results section!
3. Shape your second piece of aluminum foil into a boat – Keep in mind you will be placing marbles
(or metal washers) in it later so be sure it has a bowl shape to it.
4. Weigh your aluminum foil boat.
Record in your results section!
5. Place your aluminum foil ball into the bowl of water – does it sink or float?
6. Remove the ball from the bowl and then place your boat in the bowl of water – does it sink or
float?
Questions for Part 1:
7. If the squares of foil have the same size, same density and same masses, how can one sink and the
other one float?
8. Compare the buoyant force on the crumpled square with the buoyant force on the aluminum boat.
Do they have the same buoyant force? Why or why not?
Part 2
9. Place your aluminum boat in the bowl of water.
10. Using one marble (or other weight), place the marbles into your ship until the ship sinks. (As soon
as your boat takes on water or touches the bottom it is considered sunk).
11. Dry off your boat and marbles carefully. Then weigh the boat and marbles.
Record in your results section!
12. Record your group’s results on the class chart. Then copy the class data on a chart for your lab
report.
Questions for part 2:
13. What is the buoyant force on the empty boat? The full boat? Do they both have the same buoyant
force? Why or why not?
14. How did your boat do compared to the rest of the class? Did yours carry more or less marbles?
15. How does the shape of the boat affect the amount of marbles the boat can carry?
Lab Report Check List – Make sure you have everything!!
 Title of lab
 Introduction:
o Background information on buoyancy, Archimedes’ principle and density
o Purpose of lab
 Materials and Methods:
o List of materials used
o Summary of lab procedures
 Results – Attached results chart
 Conclusion:
o Answer “Questions from Part 1” in a paragraph
o Answer “Questions from Part 2” in a paragraph
 Put your name on it!
Results Section – Foil Boat Challenge
Part 1 Data:
Table 1: Did it sink or float?
Mass of aluminum ball = ____________________ grams
Mass of aluminum boat = ___________________ grams
Object
Ball
Boat
Sinks or floats?
Part 2 Data:
Mass of aluminum boat with marbles = ______________ grams
Boat
Number of marbles/weights
Averages=
Mass of aluminum boat with
marbles