UP! UP! AND AWAY!

Have your birthday parties ever included helium filled balloons? It is so much fun to watch helium gas filled balloons float so high above our heads. Did you notice that there are always little trinkets tied to the ends of those helium balloons. What would happen if you untied those trinkets from the balloons? UP AND AWAY! Balloons can show you a lot about aeronautics. Today’s activity will demonstrate the power of lift, or how much can that helium balloon lift. Before a balloonist launches their huge balloon, they need to know what weight their balloon can lift and to what height it will take them. If the balloonist does not know these facts their flight may not be enjoyable at all! Our commercial airplane companies are also looking at the increasing weight of the average passenger as they compute the lift power for a plane.

Now you can work with an experiment that demonstrates lift power.

Materials:
1000 ml graduated cylinder
1 inch diameter styrofoam sphere, or any shape
(a small balloon may also be used)
thread
needle
large paper clip
several washers
ceramic magnet
water
two equally thin books

Procedure:
1. Set the cylinder on two thin books so that it’s slightly elevated above the table.
2. With the help of an adult, push the needle with thread through the 1 inch diameter styrofoam sphere from top to bottom.
3. Then attach one washer on the paper clip and attach the paper clip to the thread.
4. Place the sphere and paper clip with one washer in a 1000 ml graduated cylinder.
5. Place a strong magnet under the middle of the cylinder, between the books.
6. Add water to about the 750 ml mark.
7. To launch the balloon, simply remove the magnet.
8. As you add one washer at a time, you will measure and record the volume. Remember to launch after each addition. Your goal is to continue to add enough washers to just allow the sphere to move upwards slowly, as the balloonist would like to lift slowly and smoothly .
9. With your collected data, create a graph and plot the load (number of washers) versus the volume of the system (water level in the cylinder). The graph will give a very nice straight line.