Luckily there are numerous resources on the internet and this week we tried out the balloon rockets experiment courtesy of Rolls Royce.
Points for showing your working, here's what we did.
1. Decide on a question we're going to investigate. W went with : What shape balloon will be fastest? and K decided on : What thickness of string will be fastest?
2. Hypothesise. We think the long balloon and thinnest string.
3. Establish the variables and how we'll control them - W was particularly strong on this and quickly grasped the concept of only changing one at a time.
4. Get set up and time the rocket's descent with our stop watches. K did a great job (W chose this moment to have a paddy and returned 10 minutes later!). Bit of discussion about gravity, air resistance and aerodynamics.
5. Conclusions, speed=distance/time and some maths to work out mps followed by a handy google conversion to mph. The long balloon was quickest but in the string experiment is was the middle sized string that won. K worked out it was to do with texture and fiction.
Balloon rockets
http://www.rolls-royce.com/careers/students-and-graduates/education-and-work-experience/resources-for-schools/interactive-resources-for-7-11-year-olds.aspx#activity-worksheets
