AlkaSeltzer rockets

rocket animation
Alkaseltzer Rockets – Learn about NASA’s work, Aerospace Engineering, and Newton’s Second law while making and launching rockets high into the sky!

How Does it Work?

When water is added to the Alka-Seltzer tablet, bubbles of carbon dioxide gas are given off. When the lid is fitted tightly to the canister this gas is contained within an enclosed space. As more gas is given off the pressure inside the canister rises until there is enough force to overcome the seal of the lid. The built up pressure exerts enough force to shoot the canister into the air, forming the rocket.

So the canister pops its top (which is really its bottom, since it’s upside down). All the water and gas rush down and out, pushing the canister up and up, along with the rocket attached to it.

This is the law of action and reaction. The action is the gas rushing out of the rocket. The reaction is the rocket taking off in the other direction. In other words, for every action there is an equal and opposite reaction. The rocket goes in the opposite direction from the gas, and the faster the gas leaves the rocket, the faster the rocket gets pushed the other way.
That’s engineering

  • action –
  • reaction –

Engineering ideas

  • carbon dioxide, gas, pressure, force, action, reaction

Do It
Challenges for you to work on…

  • Note that you cannot use cold water.

Learn more…