Air cannons are an iconic DIY project. You can find a lot of great examples online. There are cannons that are powered by combustion and cannons that are powered by compressed air. They can be used to fire anything from golf balls, to water bottles, to candy.
But in this project, we are doing something a little different. We are going to make a baking soda and vinegar cannon. This is very similar to the baking soda and vinegar volcanoes that we made as kids. I have just scaled up the reaction so that it can be used to send a potato flying through the air.