?? for an Engineer

[Randy]

But wasn,t this fun

[mikechell]

Yeah, this is fun. I am, after all, a technical instructor. Croxt, I did say that pressure is just another kind of force. And your definition, "force acting on a surface" is just that.
But there was the question of the trailer always being pulled towards the towing vehicle. This is true, unless you are backing up, of course.
It is being pulled by the vehicle. Since the vehicle is always under power, trying to go faster, all opposing forces are trying to slow it down. Gravity, air resistance, the weight of the trailer, the vehicles own weight and mechanical drags within the driveline.
Since the weight of the trailer is trying to slow the vehicle down, it is constantly being pulled forward, or in the direction of the towing vehicle. Thus, since the vehicle is always trying to pull away, and the trailer is always being pulled forward, it is being pulled towards the vehicle.

[croxt]

Mikechell......will need to discuss with you at the next muster.....will need to demonstrate pressure.....although pressure involves force, they are not the same.

anyway, i think Piper said it best. The point of applying the force, releative to the centor of mass of the vehicle, determines if it is being pulled or pushed. On a local analysis, the ball is actually pushing on the tongue, but the trailer is being pulled by both the tongue and ball.

Thanks Randy.....this is kinda like why do mexican jumping beans jump or the ever popular perpetual motion machine.....LOL

[Randy]

who would have thought this would make five pages?

[mikechell]

Ha ha ha ... mexican jumping beans have a larva in them. It's the movement of the worm that makes the "bean" jump.
I like the "which came first, the chicken or the egg?"
I believe in evolution, which means the egg came first. Something that wasn't quite a chicken laid the egg that hatched the first true chicken. It's genes then passed on the line that filtered into the chickens we know today.
Croxt, we will have to debate this at a muster. force is an all encompassing word for a variety of situations. Air pressure, horsepower, electromotive, hydralic pressure, all different forms of "force".