Selecting and developing activities for finding forces
Classroom Activity
for 5-11
Teacher Tip: Based on the Physics Narrative and the Teaching and Learning Issues
Ideas to emphasise here
- connect interactions between objects with the idea of a force
- adopt consistent conventions about where and how the arrows are drawn
- relate floating and sinking to forces, not to rules about displaced fluids
- relate
friction
to the mechanisms of friction - focus on the physical reasons for placing arrows
- giving real experiences of forces acting at a distance
- exploiting the tangible effects of magnets in regions of space around the magnet
- relate electric, magnetic and gravity forces, without conflating them
- separate the mass of an object from the force of gravity acting on the object, without being dogmatic
Teacher Tip: Work through the Physics Narrative to find these lines of thinking worked out and then look in the Teaching Approaches for some examples of activities.
Strategies for supporting learning
- draw on learners conception of their own actions and relate these to force
- explore and expose children's ideas of forces
- draw out children's everyday ideas about motion and the forces required
- introduce children to a new way of seeing – with forces
- convince children that inanimate things can push, just like they can
- developed the idea that a mechanism underpins the interaction that is replaced by force
- convince children that air can exert forces
- draw on children's own experience of action at the distance, probably through experiences with magnets
- draw on children's experiences, some of which will be vicarious, to establish the reality of gravity in space
- explore something of the mystery of action at a distance
Teacher Tip: These are all related to findings about children's ideas from research. The teaching activities will provide some suggestions. So will colleagues, near and far.
Avoid these
- drawing arrows next two objects, or near objects, when you intend the force be acting on the object
- don't act as if the placing of arrows is obvious and open to a simple inspection
- don't refer to forces cancelling out
- avoid using complex objects on which forces might be acting (with internally moving parts – bicycles, cars, people.)
- using friction as a blanket term, without reference to its physical origins
- treating contact forces exerted by inanimate objects as obvious
- stating, without sharing the appropriate experiences that give the statements meaning
- treating action at a distance as obviously acceptable
- acting as if the similarities between the three non-contact forces always have been obvious
- over-emphasising the similarities
- conflating the terminology and representations for the three different forces
Teacher Tip: These difficulties are distilled from: the research findings; the practice of well-connected teachers with expertise; issues intrinsic to representing the physics well.