There is a much more intuitive way you show it to a child with the following example

Walk up to a wall and push it as hard as you can. You know and can feel you are exerting a force but nothing is happening. So forces do not always result in motion they can be resisted.

The leap to understanding that the wall is creating an opposing force takes some further work so they understand what is happening when forces are resisted but at least they start with forces can be resisted.

Lets see if Paul can grasp what a child can that forces do not always lead to motion they can be resisted perhaps as a later exercise we can walk him thru that resistance to a force is done by creating a counter force.

Last edited by Orac; 11/22/12 01:49 AM.

I believe in "Evil, Bad, Ungodly fantasy science and maths", so I am undoubtedly wrong to you.