What Children Might Say or Think about Forces
Children often know what to do to make things move or change shape but are not able to describe how the size or direction of the push, pull, squeeze, or hit relate to the subsequent movement of the object. Stooping movement is usually attributed to the lack of action to keep the object moving:
'The push wore off.'
Children usually know how to stop something moving but do not attribute the stopping action to a Force in the opposite direction of the movement. They think that things that recover their shape do so of their own accord, not because of a force coming from the 'springiness' of the material. Children do not have a problem recognising movement but think the moving object, or specific parts of the object (the wheels for instance) have an in-built ability to move. Another example would be that:
'people move because they have legs.'
Similarly, children might be said to have a 'simplistic' view of the reason for things falling. Things fall because you let them go and they do not need a force, whereas you need a force to make things 'go up'.
When thinking about friction children tend to relate their ideas to how they feel:
'It stops because it gets tired'
'It's run out of energy'
Other reasons could be because the car is no longer on the slope, or because the toy is heavy.
Sometimes they introduce words such as 'power' and 'energy' to explain why things stop.
ContentMeasuring Force, Mass, Speed