This week in Summer Science Camp, Explorit’s younger campers are blasting off to the stars for an astronomical adventure. You can join in the fun at home with a balloon rocket experiment. Build and test two different models of balloon rockets with materials you can find around your house.
You will need: a toilet paper tube, two balloons, two binder clips, masking tape, string, scissors and a straw. First, set up your rocket’s racetrack by taping a length of string between the backs of two chairs. The longer the better! If you want to race two rockets at the same time, set up two lengths of string, just leave enough space in between them so that your rockets don’t bump into each other.
Now, start assembling your rockets. Blow up both balloons, but don’t tie off the ends. Secure them with the binder clips so they’re easy to release when you’re ready to race. Use masking tape to secure one balloon to the toilet paper tube. Your first rocket is ready!
Cut a piece of the straw about three inches long. Tape that to your other balloon. Now you’re ready to race.
Thread one of your rockets onto the string, but make sure to keep the string taut. Start a countdown, then release the binder clip and let your rocket fly!
What do you observe? Which rocket moves down the string the fastest — the toilet paper tube or the straw? Why do you think that is?
You can also add another variable to your rocket races by trying different kinds of string: a thick yarn, a coarse rope, a thin shoelace. Which rocket flies best on which string?
Your balloon rocket is being propelled across the room on your string using the same principle that launches real rockets into space: thrust. Thrust happens when a force pushes an object in a single direction.
In the case of a real space rocket, the rocket fuel creates a force that pushes down against the ground and propels the rocket upward into space. In the case of our balloon rockets, the air pressure being released from the balloon pushes our rocket in the opposite direction along the string.
When you blow up a balloon, you force air molecules inside a tight space. When you close the end of the balloon, you trap those air molecules in there, creating air pressure.
If they get a chance, those air molecules will want to move away from each other and reduce the pressure. That’s why when you release the end of the balloon, all the air comes rushing out. That rush of air creates the thrust to propel our balloon rockets.
Explorit’s coming events:
* Explorit’s “Beautiful World: Science and Art” exhibition is open to the public from 1 to 5 p.m. every Wednesday, Saturday and Sunday, and 3 to 6 p.m. every Friday. Admission is $5 per person; Explorit members, teachers and children 2 and under are free.
* Interested in membership? Think your Explorit membership may have lapsed? Call Explorit at 530-756-0191 to check or sign up.
* Don’t miss Explorit’s summer field trip to the Discovery Museum’s Challenger Center on Aug. 6 for fifth-, sixth- and seventh-grade students. Search “Explorit” on brownpapertickets.com.
* Save the date: Sunday, Sept. 7, for the “Final Blast Festival and Chemistry Show” that celebrates the end of Explorit’s Summer Science Camp season and is a fun way to start the new school year.