We made flying film canisters before, click here to see our Kid Friendly Film Canister Rocket, but we thought we'd try something more intense. In our fourth grade class we use "exploding" film canisters to demonstrate how an explosive volcano builds up pressure. In our eighth grade class we make rockets to discuss Newton's Laws of Motion. During our summer camps and presentations we made these Flying Film Canisters with a Twist because they are freaking awesome.
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Step 1: Materials
For this activity you will need some 3D prints. Hey wait don't stop reading if you don't have a 3D printer. Just get a bunch of friends together. They can all flip their film canisters over at the same time. It is amazing when 24 students all flip their film canisters over at the same time. Fat Cat made this for days when friends can't come over or for a cool demonstration.
The first 3D print is a film canister holder. It simply hold 9 film canisters in place. This is needed to flip all nine film canisters at the same time.
The next 3D print is the insert that goes into the film canister. Originally designed so fourth grade students did not panic when doing the film canister rockets. The insert keeps the Alka Seltzer dry while snapping on the cap, preventing the chemical reaction.
You will also need -
9 x 35m canister with lid that snaps closed inside the canister. "Fuji Style"
Effervescent tablet like Alka-Seltzer. Generic works fine.
We do not suggest having kids use a film canister rocket without adult supervision. The rockets accelerate so fast that they could hurt someone.
Step 2: Place the Canisters
Take the film canister holder and set it down a firm surface.
Place the film canister firmly in the holes face down. See pictures for visual.
Step 3: Flip
Flip the film canister holder over.
The holder will now have all nine canisters attached.
Step 4: Break
Break the Alka Seltzer tablets into fourths.
Set aside to a dry location for later.
Step 5: Water
Add water. Here we show adding 15 ml of water with a pippet.
Using a Tbs. is a quicker way to add the water.
Step 6: Insert
Add a dry 3D film canister insert, tiny holes up.
This will keep the tablet of Alka Seltzer from getting wet for now.
Step 7: Tablet
Safety glasses on yet? Probably should have them on.
Add the 1/4 tablet of Alka Seltzer to every film canister. Place carefully onto insert.
Step 8: Snap
Snap the lids on. Press each lid firmly on. Make sure they snap.
This is the part that always got our fourth through eighth grade students and why we made the inserts. Without the insert the chemical reaction is happening already and the students could panic. When they did panic they would not close the lid all the way and the activity would fail.
The inserts work great for the nine canister demo or for each individual student doing their own canister.
Step 9: Flip
Are you safety glasses on? They should be!
Flip the nine film canister holder over. Shaking a little helps the reaction occur more quickly.
Watch your film canisters take off FLYING!
Step 10: Why Orange?
We took our first pictures with white film canisters and parts. It made it really hard to see in the pictures. We ended up painting the film canisters in orange so we could take pictures especially when the canisters started flying.
Step 11: The Science!
There is a lot of science behind the rocket going up. Newton's Three Laws of Motion come to mind for us. One being that an object at rest will stay at rest unless acted on by outside force and an object in motion will stay in motion unless acted upon by an outside force (simplified version). The rocket would just sit there if there was no force from the chemical change that is taking place inside the canister. The build up of pressure is released out the bottom of the rocket which causes the rocket to move. The rocket would continue to move up but gravity is a force that stops the rocket from continually going up.
Second law of motion essentially says that the more mass an object has, the more force will be needed to get that object to move or stop moving (simplified). Force = Mass x Acceleration (f=ma). If we put more mass on the rockets the more force will be needed to launch the rockets. In our eighth grade science class we experiment with adding different amounts of mass.
Third law is action / reaction. For every action there is a reaction. If you push a wall the wall pushes back. Try it with skates on and you will see what I mean. Think of a balloon that is filled with air. Let go of the balloon and the balloon moves in the opposite direction the air is coming out of - action / reaction. The rocket has gasses shooting out the bottom of the canister downward (action) and the canister moves upward (reaction).
Runner Up in the
Make It Fly Challenge