Push and Pull Forces
We made a balloon rocket in science today. We learned that a force is a push or a pull. Force gives an object the energy to move, stop moving, or change direction.
How does our balloon rocket work?
It’s all about the movement of air inside the balloon. As the air rushes out of the balloon, it creates a forward motion called thrust. Thrust is a pushing force created by energy. In the balloon experiment, our thrust comes from the energy of the balloon forcing the air out. In a real rocket, thrust is created by the force of burning rocket fuel as it blasts from the rockets engine – as the engines blast down, the rocket goes up!
You will need:
1 long piece of kite string
1 plastic straw
1. Tie one end of the string to a chair.
2. Put the other end of the string through the straw.
3. Pull the string tight and hold onto this end.
4. Blow up the balloon. Don’t tie it. Pinch/twist the end of the balloon and tape it to the straw.
5. You’re ready for launch!
After we had our rockets tested we went about measuring the distance that each rocket traveled. The maximum distance that the balloon could travel was 3 metres = 300cm.
Oval Balloon: Traveled 2 metres & 30cm = 230cm.
Cyclinder Balloon: Travelled 3 metre = 300cm.
Sphere Ballon: Travelled 3 metre = 300cm.
After discussing the test we decided that we needed to have longer kite string available for the test since two balloons reached the maximum length available. Also, we said that we could not be sure if it was a fair test since we didn’t know how many breathes went into blowing it up each time. We decided that we would use a pump to complete the test again in the next couple of weeks and post our results again then. We can’t wait for this investigation to continue.