Chemistry Rocket Engineering
Today your team becomes rocket engineers. You will build a rocket, launch it with a real chemical reaction, and then do the part that makes it engineering: change your design, test again, and make it fly better. Real engineers at places like NASA do exactly this. They test, measure, change one thing, and test again.
When an Alka-Seltzer tablet hits water, it fizzes. That fizz is a chemical reaction making carbon dioxide gas. Sealed inside the canister, that gas has nowhere to go, so pressure builds and builds until it pops the cap off and launches the canister.
For every action there is an equal and opposite reaction. The gas pushes the cap down into the ground, so the rocket is pushed up into the air. That push is called thrust, and it is the same idea that launches a real rocket.
See the reaction and the launch before you build. Watch what makes the canister take off.
Every rocket has parts with a job. You will build yours from cardstock around the film canister engine.
Use the cardstock to design your rocket. There is no single right way to build it, so make it your own.
A nose cone for the top and fins for the bottom. Roll a cone, cut fin shapes, and tape them to your film canister. Want more? Add a full fuselage body tube around the canister and decorate the whole thing.
Keep it light, and never tape over the cap. The cap has to snap on and pop off freely, or your rocket will not launch.
Your first launch is your baseline, the result you will try to beat. Do these steps quickly once the tablet is in.
In your design log, write down your baseline: how much water, how much tablet, about how high it launched (low, medium, high), and the time before it popped.
Now improve it like an engineer. The golden rule of a fair test: change only one thing at a time. If you change two things at once, you will not know which one made the difference.
Pick one variable. Launch. Eyeball the height and time the seconds before it pops. Write the trial in your design log. Then change one thing and go again. Run as many trials as you can.
Before each launch, tell your group what you think will happen and why. Then see if the rocket agrees with you.
Look back at every trial in your design log and compare.
More tablet or more surface area (crushing) makes gas faster, so pressure builds quicker and the cap pops sooner. The right mix of water and tablet builds the most pressure before it blows, and more pressure means more thrust.
You built a rocket, launched a real chemical reaction, and improved your design with evidence from every trial. That is exactly how engineers turn a good idea into a better one. Nice flying, team.