(
When we think of rockets we often tend to think of giant metal rockets, blasting up into space on a column of jet fuel. A rocket doesn’t need to shoot fire to get going. Isaac Newton’s laws of motion let us use lots of things as rocket fuel, even air!
Materials:
For your rocket launcher you will need:
- One 10-foot PVC pipe, 1/2-inch in diameter
- One 1/2-inch 90-degree PVC elbow
- Saw or PVC cutter
- Lots of 2-liter bottles
- Duct tape
- Twine
To build your rockets you will need:
- Scotch tape
- Old magazines (the kind with a staple in a center crease)
- Cereal boxes
- Scissors
Process:
- Using your saw or PVC cutter, have an adult cut your 10 foot PVC pipe into the following lengths:
- One 5-foot piece
- One 2-foot piece
- One 1-foot piece
- Two six-inch pieces
- Use the 90-degree elbow to connect the 5-foot piece and the 2-foot piece forming an L-shape. Stick ‘em in there tightly. You can glue them together if you want but sometimes the launcher is easier to transport if you can take it apart.
- Using your twine, tie the two 6-inch pieces across the 5-foot piece. They should be perpendicular to the 5-foot piece and about 3 feet apart from each other to act as stabilizers. The 2-foot piece should be facing skywards. Tie the twine tightly and secure it in place with some duct tape.
- Your launcher is almost done! Stick the open end of the 5-foot piece into a 2-liter bottle. Push it about an inch or so into the opening in the bottle. It will fit snugly but secure it with some duct tape just in case.
- Now it’s time to make a rocket! Open your old magazine to the very middle and have an adult remove the staples for you. Pull out a sheet or two of paper.
- Using your last piece of pipe, the 1-foot piece, roll the pages around the pipe. You can go long-ways or short-ways, whichever you like. Once the paper is rolled all the way up around the pipe use the scotch tape to tape it lengthwise, creating a paper cylinder. Don’t make it too tight on the pipe or it won’t fit onto the launcher!
- Take your rocket body off the pipe. Using your scissors, make four 1/2-inch cuts in one of the open ends in an X-shaped pattern. Fold the four flaps down on top of each other and tape them shut until the top of your rocket is airtight.
- Cut some fins, whatever shape you like, out of the cereal box and tape them to the bottom of your rocket. Remember: fins are important for a rocket to fly straight but too many fins will weigh it down and make it fly a shorter distance.
- Slide your rocket onto the end of the 2-foot piece. You’re ready to launch! Give a countdown and then stomp as hard as you can on the 2-liter bottle.
Summary:
How far did your rocket go? A well-built rocket with a really good stomp can fly close to 200 feet in the air!
Big space rockets use Newton’s third law of motion to get moving: for every action, there is an equal and opposite reaction. The rocket fuel pushes down (action), and the rocket gets pushed up (reaction). Your rocket is a bit different. Newton’s first law provides the mechanism to get it moving: an object at rest tends to stay at rest unless acted upon by an outside force. The air in the 2-liter is at rest until you, the outside force, stomp on the bottle and get it moving. The rocket is at rest until the air hits it, putting it into motion, and then it shoots up into the sky!
You can get 20-30 good stomps out of one 2-liter bottle by blowing into the launcher and puffing it back up with air over and over. Make sure you put your hand around the launcher so your lips don’t touch the pipe, though! When your bottle is about finished, just take it off and pop a new one on. Experiment with different sizes and shapes of rockets to see what flies the best!
Want more Saturday Science? See all of our at-home activities on the blog or on Pinterest.
