This is a super simple science experiment with vertical balloon straw rockets for kids.
Teach kids about Newton’s third law of motion or simply have some fun!
My kids just love balloons.
Recently we started showing my son how balloons fly crazy when you don’t tie them off and just let them go.
I was watching TVO Kids with them the other day. I love watching Bitz and Bob because they always have some kind of science experiment to do with your kids at the end.
On this particular episode they did balloons on a string.
This instantly reminded me of a balloon rocket science experiment from when I was a kid!
I grabbed the supplies and took my kids outside to give it a try a few days later since it was raining that day.
At first we just made our balloon rockets with string, straws, yarn and packing tape. Since that’s what I had on hand.
Later we turned them into real rockets by adding fins with little pieces of paper.
I also realized that thinner tape strips work much better. So we switched to using thin painters tape!
Also recommend packing tape as it adheres strong enough to stay on but not strong enough to pop the balloon.
For This Balloon Straw Rocket Science Experiment You Will Need:
- 2 balloons
- 2 straws
- long piece of string or yarn
- painters tape
- two clothespins (optional)
- paper (optional)
Setting up Your Balloon Rockets Science Experiment
Find a Location for Your Balloon Rocket Course
First thing you need to do is decide where you are setting up the experiment course.
We did our balloon rocket race between two trees.
But this can be done indoors also between a chair and a doorknob or between two chairs.
Turn Straws Into Rockets (Optional)
Next, cut a piece of string or yarn long enough to go from one end of the course to the other and back again.
Or two pieces long enough to go from one end to the other and be tied at each end. (But don’t tie them yet!)
Next you need to get the straws prepared.
If you are choosing to decorate your balloon rockets then here is what we did. Older kids can do this part on their own!
Cut 3 triangles to use as the fins on the back of the balloon rocket. You want to have one of the corners a 90 degree angle (approximately).
Tip: we made this easy by taking a square and cutting the corners off diagonally.
Next you want to tape 3 of these onto one end of a each straw to make it look like a rocket.
I taped on both sides of each triangle to make sure they would stick out and not just fall flat onto the surface of the straws.
If your kids love science and balloons as much as mine then they will love this Blowing Up a Balloon Experiment!
Setting up Your Balloon Rockets Course
Now it’s time to tie up the balloon rocket course.
Attach the string(s) to your finish line or ending point.
Thread the straws onto the other two ends of the string(s) that are not tied on yet.
Tip: If you made them look like rockets then make sure to have them both point towards the tied end.
Once the straws are on you are free to tie the other ends to your starting points.
Tips: Make sure there is enough room between the starting points for the balloon rockets to not be touching once they are blown up and taped on. Also make sure the string(s) is tight enough that they are straight and not droopy.
Note: If you have more than two children planning to participate you can always make more course lines by adding another string to the ending point and tying the other end to a 3rd or 4th starting point with more straws and balloons!
Now Tape Your Balloons to the Rocket Course
Your final step in preparations will be attaching the balloons to each straw!
First thing to do is blow up your balloons. They need to be attached to the straw when fully blown up.
This is where I found the clothespins to be helpful!
TIP: After I blew each one up I would give the end a tiny twist and pop a clothespin one at the twist to stop it from deflating. (Optional as we did it many times before I thought of it.)
Once the balloons are blown up tape to the straws with the openings facing the back of the rockets.
I actually did them backwards the first time. Oops!
Tip: If you do them backwards don’t attempt to take the tape off! It’s better to let them deflate and hope that the tape will come off on its own… my balloons popped and I had to grab some more.
This Hidden Colors Experiment is another one of my sons absolute faves!
Vertical Balloon Rockets Science Experiment 3-2-1-Blastoff!
You are now ready to start the balloon straw rocket race!
Have your kids each hold one balloon and have it as far back on the starting line of the string as possible.
Or if only one child is participating they can hold one in each hand or you can hold one.
Start your countdown!
Finally, let go of the ends of the balloon rockets at Blastoff and watch them zoom to the other end of the string to the finish line!
This is a great time to talk about Newton’s 3rd Law of Motion: Every action has an equal and opposite reaction.
The air blows out of the balloon (action).
The balloon rocket moves forward (reaction).
Also take the time to discuss what the balloons did. Did it go straight? Spin around the string? Get stuck half way?
Tip: Having the balloons different colors helps to keep track of your results if you choose to document this like a real science experiment.
We did this balloon straw rocket experiment tons of times over!
Have your kids bring the straws back to the starting point and blow up the balloons to go again!
If the balloons fall off, no worries, just tape them back on.
And if they don’t fall off then have fun blowing them up still attached to the string. Lol.
Extend the Science Experiment
Try different set-ups to see what happens.
- What happens if one is blown up smaller than the other?
- What if you tape the balloon on sideways or on an angle? Does it spin?
- What if you don’t actually let go completely and just let the air out? Does it make your hair or clothes move?
- Try different sizes and shaped balloons.
- What if the triangle fins are on an angle?
- Try less fins or no fins?
- What if the fins are really big or smaller?
- Cut the string and stick the front of the straw into the end of the balloon and use a small elastic to secure it. Blow it up using the straw and then watch it fly freely. See where it goes like Mombrite did.
Keep going on the topic of actions having an equal and opposite reaction.
Or if you are ready for a different experiment now, check out one of our personal favorites: Magical Color Changing Milk Experiment