Answer:
Dr Hewitt is able to break the piece of wood in his demonstration given that he had knowledge about the concept of momentum, which is esentially the product of the mass and speed of an object.
Aplying this idea, he used the correct momentum of his hand over a short period of time and that is how he was able to break the piece of wood.
Answer:
I would start with simple definitions to teach them, the words would depend on the grade they are in, then the words would get harder as we make progress.
Explanation: Hope this helps:).......if not sorry for wasting your time:)