sci.physics.electromag

maxwell wrote:


>
> Benj, there is another concept that justifies why things move apart
> from 'force'. Just to make this interesting, check out p.19 of the
> Principia (transl. Motte, Prometheus) & remember, Newton wrote in
> Latin, so his original word was 'vis' that today is translated as
> 'force' but modern physics (like Newton) has another term.

Vis also means energy or action.

But all this is bafflegab. We resolve the meanings by using mathematics.
Force is the change of momentum (what Newton called motion) in time.

F = dp/dt. This is true classically and relativistically.

Bob Kolker