1. Paul Malpass – National Lead Post 16 Science

2. Active Learning: Mechanics Friday 13.15 to 14.15 Learners can struggle with the whole concept of moments. This ‘hands on ‘ session will offer a ‘Blue Peter’ style investigation into moments Could this be a lead into balancing equations?

3. Outline First part, Getting to grips with the stuff (20 minutes) Second part, How might you use this in your teaching (20 minutes) Final part, Report back, share ideas and possible teaching scenarios (20 minutes)

4. What is a moment “Think of some examples of where force cause a turning effect.” “I’d like you to describe how you’re applying the force.” “Where is the rotation coming from?” “Where is the centre of the rotation?” Some diagrams on your mini white boards please

5. Some examples

6. A moment is is defined as a force multiplied by the perpendicular distance between the line of action of the force and the pivot. Engineers may call this ‘torque’

7. A Clockwise moment Sketch on your mini white board a clockwise moment

8. Please set up your CD balance

9. Introduction to learners Show the group the disc without any magnets on it. With the A–B axis horizontal, place a pair of magnets (one either side of the disc) on the horizontal axis 40 mm to the right of the pivot (use the hole in the magnet to position it accurately on the graph paper). Show the learners that this causes the disc to rotate and settle with the magnets directly below the pivot. Now hold the disc with the A–B line horizontal. Ask the group to work in pairs and put in order of preference where a pair of magnets should be added to the left hand side of the pivot in order for the line A–B to remain horizontal.

10. What is happening? Why? As you accept learners’ suggestions, ask them to say why they have chosen the points. Now place the magnets at each position in turn and observe the effect, so that the learners can assess whether their predictions were correct.

11. Demonstrate clearly that while position W will not produce an equal moment, any position on the line X– Z will produce an equal moment as the perpendicular distance between the magnet and the pivot is equal to that on the right hand side (40mm). Equal moment means that ‘the anticlockwise turning effect is equal to the clockwise

12. Practice getting the CD to balance It is now possible to use the mass and distance from the centre of the CD to produce a moments worksheet Anti clockwise momentClockwise moment Mass (!)DistanceMass (!)DistanceMass (!)DistanceMass (!)Distance

13. How might you use this in your teaching? Working in groups of 2, How would you use this is your teaching? What level of student could CD balance be used with, level? Thinking outside the box, what other possible uses might this idea have when teaching mathematics.

14. Feedback A very brief feedback from each group

15. Resources are online QIA excellence gateway - Engineering resources