Wednesday, May 6, 2015

Two-Stage Balloon Rocket - Take Two



The children got up this morning, ready to give our two-stage balloon rocket a second go.

First though, we decided we better make sure our basic balloon rocket set-up was good, so we set up the experiment with a single, inflated balloon, taped to a piece of straw, threaded onto piece of string, pulled tight horizontally.


When we let the balloon go, it spiraled in place around the string...


...and broke loose from the tape, without moving the straw forward on the string.


We thought, perhaps, we had the balloon taped too tightly to the straw.  So, we modified our tape...


...to create a gap between the balloon and the straw.


This time, when we let the balloon go, it still spiraled slightly, and the balloon still broke free of the tape...


...but not until it had moved the straw all the way down, and bounced off E's hand, at the end.


Satisfied, we repeated the single balloon experiment, with the string tilted upward, like we had had it for our first two-stage attempt.


Again, the balloon carried the straw to the end of the string, before breaking loose, and continuing on another few feet beyond E.


Using our modified tape design, we added the half of the Styrofoam cup, and a second straw with tape...


...for a second (first stage) balloon.  Put together correctly, the second balloon is supposed to be inflated enough to hold the neck of the first balloon shut against the edge of the cup.


Our first balloon was quickly deflating, and it was impossible to release them both at the same time.


We tried blowing more air into the second balloon, to make it bigger, but only succeeded in breaking open the cup.


I reluctantly agreed to sacrifice one of my sturdier, waxed paper, coffee cups.


We added some tape to the cut edge of the cup, to protect the balloon, and found that with a sturdier cup, it was possible to keep both balloons inflated, holding only the neck of the second balloon.


Unfortunately, when we let the balloon go...


...both balloons deflated, and broke free of the tape, without moving the straws forward.


We tried securing the first balloon to its straw, with extra tape...


...which did result in a nice break-away of the first stage of our rocket...


...but not only did the primary balloon "engine" fail to propel the rocket forward at all, the two balloons stuck together.  So, as the first balloon deflated, it pulled on the second balloon...


 ...keeping it from moving forward either.


Finally, we tried taping the cup to the second, or primary balloon (I know it sounds confusing - it's the primary part of the rocket, but the second balloon installed), to the cup.


This kept the cup, and second balloon from breaking away...


...but did allow the first balloon to move forward.


The idea of course, is to get the primary balloon to give the rocket a little push forward, then break away with the cup, allowing the secondary (or front) balloon to continue on even farther.  We are still missing the initial push, and proper breakaway.

However, it was about then, that a butterfly flew by the window...


...and the hunt was on.

There are days that almost unschooling a family of six feels a lot like a productive sort of ADD.

5 comments:

maryanne @ mama smiles said...

Okay, you were much more persistent with this than I would have been!

Phyllis said...

Your kids are much more patient than mine.

Ticia said...

But you had a bunch of tries, as everyone else said, my kids would have already been gone.

Of course it's not that my focus is all that good either.

Natalie PlanetSmartyPants said...

You are raising a very resilient scientists. I am impressed with several tries of this. I am sure it was super easy in the book :)

An Almost Unschooling Mom said...

Natalie - Yes, I should know better than to trust an experiment with only pencil drawn instructions - those always look easier than they turn out to be.