Do you have a budding little scientist in your home? Kids can become their own rocket designers with this fun experiment that shows how mass, thrust, and force are crucial for a successful launch. Teaching the scientific principle of air pressure, this experiment for kids ages 8 – 12 is the perfect indoor activity when the weather outside is anything but delightful. There are plenty of other great projects to explore, all of which can be done with things you’ll find in your kitchen cabinets, in Dr. Michelle Dickinson’s book, Kitchen Cabinet Science Projects.
Equipment & Ingredients
- Drinking straws
- Clear tape / sticky tape
- Cut a strip of paper 1 to 2 in (3 to 5 cm) wide.
- Trim the strip so that it winds around a pencil once, to form a tube. Use sticky tape to
hold the tube shape in place.
- Remove the tube from the pencil and seal one end by folding over and securing
with sticky tape.
- Use the remaining paper to cut out fin shapes and tape onto the sides of the rocket at
the open end of the tube.
- Place the rocket over the end of a straw and blow hard through the straw to launch it!
The Science Behind the Straw Rockets
All rockets, whether made from paper tubes or carbon fiber, require a few things to fly well. First, they need to have enough force to start moving. When you blow air into the straw, it tries to flow out of the other end. However, because the rocket is blocking the end of the straw, you need to blow hard in order to create enough force to push the rocket off the end so that the air can pass through the straw. The harder you blow, the more energy you provide and the farther your rocket will fly.
The shape of the rocket is also important, as air resistance can cause drag and slow it down. Drag is the force of air pressure that pushes against the rocket. Long pointy shapes experience less drag than large round shapes and so will fly farther. Fins stabilize the rocket as it flies through the air, helping to keep it balanced and reducing the chance of it spinning or tumbling, so it can fly farther and for longer.
Eventually, gravity will pull your rocket down. The heavier your rocket, the more force will be required to make it fly a given distance, so the trick is to use as little paper and tape as possible while using enough to still hold it all together.
- What happens when you change the flight path of your rocket? Does it travel farther if you point it up or straight out? Why do you think that is?
- Add another fin to your rocket. How does this affect how your rocket flies? Why do you think the additional fin does this?
- Do you think you could make a larger rocket that fits over a paper towel tube? Would it fly as well if you blew it through the tube?