Jet Power
Word Version of this page

This week’s mission is to find out how a jet engine works, all from the comfort of your own classroom.

You will need
A long piece of fine string (perhaps long enough to go across the classroom)
A drinking straw
A balloon
Some sticky tape

Pass the thread through the straw and fasten each end of the string at different sides of the room. (You could just fasten it between two piece of furniture, or down a corridor).
Blow up the balloon and hold the end so the air does not escape.
Fasten the balloon to the straw using some sellotape (the balloon should be lengthwise as shown in the sketch below).
Release the opening to the balloon and watch what happens.

What happens to the air inside the balloon?
Which direction does it go in?
What happens to the balloon – what direction does it go in?
This experiment helps us understand how a rocket works.
Which part of the experiment is meant to be the rocket?
What does a rocket push out?
Does a rocket have tanks full of air? (If not, then what does it have?)


Science tells us there is a push to the left then there must also be a push to the right. All pushes and pulls come in pairs.
You can also see this if you have two people on roller-skates.
Place the two people facing each other. Get person A to push person B. Person B will move away, but so will person A.

Our world is full of pushes and pulls. When you sit on a chair you are pushing on it.
Try to think of ten pushes or pulls that you need right now!