Spark Tees Valley
This session is focussed on effective use of variable control when investigating in science. Using the ‘Post It’ method, pupils will identify the variables in a given context and develop an understanding of which ones to control and which ones to measure. The context for this work centres on wind power in a form that children will be familiar with.
It can be adapted to using kites, creating parachutes to drop an object from a height, sail powered cars and anything where air resistance affecting motion can be applied.
- What is a variable?
- How can we use knowledge of variables to find out information?
1) IDENTIFYING VARIABLES
Using the examples provided on the accompanying materials, ask the children to identify all the things that could change in each situation. This can be a whole class
discussion but likely organised as a ‘prompt, children work in pairs, feedback’ session.
There is a teacher crib sheet to help prompt the discussion. For many classes coming to this for the first time, they will improve their skills and ability to identify
variables (and think of odd ones!) as the session progresses.
2) AIR RESISTANCE
Ask for a volunteer. Give them a piece of A4 paper. Ask the rest of the class to quickly draw an experiment using
the volunteer and paper to see how long it will take for the paper to drop to the floor (example supplied). Ask them to identify the variables.
After some feedback and discussion show the children the ‘Post It’ planner, ideally give the children one each or use the digital version.
Demonstrate how the variables all start on the diagram but then are moved to show how they must be considered as change/measure/control (short video demonstration supplied).
Ask for another volunteer and give them a piece of A4 paper too. Ask them to scrunch up the paper into a ball.
Can the class adapt their variables on their planners to allow for this new variable?
What do they think will happen when the paper is dropped? What has caused the different result?
Discuss feedback and focus on: friction and air resistance.
3) AIR RESISTANCE AS POWER
Discuss the idea of the air as a force that can slow movement through it. Depending on the class this may also link into
work on solids liquids and gases. The video linked to activity 2 also includes animations to help understanding. Put a fan or hairdryer on a desk and point it upwards.
Ask a volunteer to hold a piece of paper above it. What will happen when the paper is dropped if
a) the device is left switched off
b) the device is switched on?
Discuss then demonstrate. How can this force of air moving be useful? The video to the right can draw the discussion to the role of wind farms such as Dogger Bank and the link below it allows a quick exploration of what it is and where if it is useful to pursue it.
Can children think of other uses of wind power?
Tip: Lead the conversation to sails!
Ask the children to think of a way that they could test sails to see which is most effective.
- Show them the foil trays and drainpipe ‘test track’.
- Can they sketch the experiment and add the variables?
Key variables that they could change:
- Size of sail
- Shape of sail
- Material for sail
- Position on boat of sail
It is up to the children which they test along with availability of materials. Use the Post It planner to plan the experiment and children undertake it.
Below are links to examples and resources required. Ideally the children will work electronically suing the Keynote version. But print out and PPT versions are also included for teachers with restricted access.