Re: The rope

Jonathan Thornburg [remove -color to reply] il 25/05/2025 09:53:48 ha
scritto:

...
The key distinction is that Newton was referring to a situation where
the rope is treated as massless, with no forces acting on it except for
the pulls (tension) at each end. 
...

It's not a fundamental distinction and Newton never said it.

In any case, regardless of what Newton said (or didn't say), the
absence of mass doesn't change anything I wrote

The rope has no mass? Okay, it has no mass.

Are you saying that there are two tensions at the ends of the rope? Of
course there are!

On one side there is the tension caused by the force of the horse and
on the other there is the tension caused by the force of the stone.

The horse pulls the rope forward (action) and generates its tension,
the stone pulls backwards (reaction) and generates the other tension.

The rope (with or without mass) is in the middle and must move
accordingly: if the horse pulls more the rope *must* accelerate
forwards, if it pulls more the stone *must* accelerate backwards, if
they pull equally it cannot accelerate.

So just look at how the rope moves to understand if the action wins or
if the reaction wins or if they are equal.

Luigi Fortunati