Getting the wrong end of the stick (or screwdriver!)
Teaching Guidance for 11-14
The wrong lever
Wrong Track: They must make those big, long screwdrivers like that so that they can turn screws more easily.
Right Lines: The length of the screwdriver can't help you with the turning effect. The only way of increasing the turning effect is to have a thicker handle (thereby increasing the length from your hand to the pivot point or axis).
Different uses for the same tool
Thinking about the learning
Household tools, such as screwdrivers, are often used in ways which were not intended in their design. Think about the line of action of the force both to be clear and to avoid nasty mistakes.
Thinking about the teaching
The screwdriver provides a good example to really challenge the pupils' understandings of levers. The key point is that a longer screwdriver does not provide a bigger turning effect. Screwdrivers are only made longer to provide easier access to difficult screws.
In describing the action of a screwdriver you need really clear diagrams to hand – or better still a large version of the tool itself as well as the diagram.