?? for an Engineer

[Randy]

OK we had this discussion today, When towing the boat, are you pullung it or actually pushing it? The way it was presented , is that the ball actually is pushing the trailer down the road. Who would figure that.......?

[BigcatLee]

thats a good question Randy, but I can see where you are pushing and not pulling.

[croxt]

without getting too technical....like i could......the only time the trailer is pushing the ball is when the pulling vehicle is slowing down and the forward momentum of the boat and trailer are trying to "push" the vehicle forward.

This is the same as a train and engine.

but for all intents and purpose...the ball is pulling the trailer.

clear as mud?

[Gentleben]

Common sense , plus the laws of gravity would dictate that you are pullin instead of pushing , unless you are backin your trailer into the water..:D
Ok BigCat, Xplain yourself, how do you think it is pushin...............

[Randy]

this is getting good.
It was explained that the vehicle and the hitch is in front and we traditionally think of it as towing.
The contact point is the ball where it fits into the "socket" of the trailer, as the vehicle moves forward, the ball pushes the trailer forward.
I can see it now, "VEHICLE IN PUSH" instead if in tow...

[Gentleben]

Oh my God!! I see where this is going is the glass "1/2 full" or "half empty"??
We had a situation at work one time and got into the biggest, hottest discussion on whether the cloumn level was "backing up" or "not going forward".What is the differenece?? The column was not moving, so what's the diff if the trailer is moving??
I choose to pull my trailer and have my vehicle in the front pulling the trailer, in my simple way of thinking if i was gonna push it I would get behind it and drive my outboard thru my radiator while i attempted to push ..You all must ah been pretty board to come up with a discussion like that!!BWAGHAHHAHAHAHAH

[Gentleben]

Here's a good one for you, "when we were in the air, we talked about girls and when we are with girls we talked about being in the air" now who said that?

[dpiper]

I don't get it?

[reedlv]

The same could go to towing a vehicle. Are you actually pushing or pulling the chain or what every is towing the vehicle? If the chain does not cross in front of something. The system referred to as towing will not work.

[Gentleben]

You don't get what ???

[mikechell]

Well, I have to put in my two cents worth. First of all, the ball is pushing the HITCH ... but the rest of the trailer weight is being pulled by the hitch. So the towing vehicle is towing the trailer.
Secondly, I don't know which pilot said it, Ben ... but I understand it. I think it's that way for all young men, no? No matter what you are doing, you are thinking about the ladies. When you are with the ladies, you try to impress them by talking about what you do for a living.

[Randy]

we may be onto something here.

[dpiper]

Wait a minute, let me grab my slide rule out of my pocket protector. If I was to take my pointer and middle fingers and stick them (one each) in randy's hugh nose and then led him to the lake would I be pushing or pulling him?

Hmmmmmm?:confused:

[reedlv]

Maybe pulling is a reaction of pushing something?

[Randy]

I was laughing so hard I forgot what to post.

[Randy]

After thinking bout it, OK, the ball pushes the trailer at the POC. (that is point of contact) At what point does the pulling/towing come in to play.
does all the weight need to be in front to be pushed as in the traditional sense? At first I would have argued that it was being pulled, now I am not sure.

[reedlv]

piper that is another way to look at it????

[reedlv]

Maybe this is why they put "IN TOW" on the back window of vehicles. They could not agree if they were pushing or pulling it?????

[reedlv]

Piper that maybe considered towing Randy to the lake????

[Catfish Jac]

Kinda reminds me of when my HS Physics teacher asked us: What makes a car go? His answer: the road, it pushes the car forward.

JAC

[saundecw]

Looks like a research project and the more fishing done, more data will be collected. Proceed with the research!

[Catfish Jac]

Maybe you can get a gov't grant!

[Steve]

I have a belly button.....

[dpiper]

From dictionary.com.

PULL: To apply force to so as to cause or tend to cause motion toward the source of the force.

PUSH: To apply pressure against for the purpose of moving: push a shopping cart through the aisles of a market.

[Randy]

maybe I am reading this wrong but both could apply.

[dpiper]

But one is more accurate than the other. Try and figure that one, "more accurate".

[Randy]

http://www.m-w.com/dictionary/push
to press against with force in order to drive or impel b : to move or endeavor to move away or ahead by steady pressure without striking

[Randy]

We may be onto something.
Now, figure this in, TOWING is it pushing or pulling?
If we have been pushing all these years, then the Transportation code may have an error or at least a defense.

[reedlv]

Piper has put a new spin on things. The only differents in push and pull is apply force or apply pressure. Now we should determine what it means to apply force? Then we should determine what it means to apply pressure?


This is really getting deep?????

[Gentleben]

:bolt: Only Piper could get away with that one !! You all are killin me !!!:mad:

[Steve]

The factor that actually determines whether an object is being pushed or pulled is based on the location of the motive power in relation to the object coupled to it irrespective of the type of coupling.
If the motive power preceeds the load while under accelleration, the load is being pulled, if the load preceeds the motive power while under accelleration it is being pushed.

I still have a belly button.

Steve

[Randy]

Is that in theory? I couldn.t find that in Websters. Helps me.......

[tylerdan]

Perhaps the trailer is neither pulled or pushed. Per Pipers definition,"PULL: To apply force to so as to cause or tend to cause motion toward the source of the force", the position of the trailer is static in relation to the source of force. As the source of force moves forward or backward, so moves the trailer but its relative position does not change. The act of of coupling the trailer to the vehicle merely enlarges the size and mass of the vehicle. The question then becomes whether the motive force (i.e. the vehicle power train) is pushing or pulling the vehicle!

[mikechell]

Now we get into physics. If you consider a balloon, with the air escaping from it, the forward force is being applied from inside the balloon, at the point opposite the escaping air. Opposing air pressures create forward motion. The odd "flight pattern" is caused by the steering effect of the "nozzle".
With a motor vehicle, the force is being applied at the contact point between the wheel and the ground. There is no opposing force, except those the thrust has to overcome. All of these forces detract from the base horsepower, giving you the final horsepower at the wheel. So, the towing vehicle is applying the force. (Force and pressure are two words describing the same thing. Actually, pressure is just one of many types of force.)
The trailer IS being pulled towards the vehicle, at all times. Even though is relative position never changes, if the force is removed, it will no longer stay with the vehicle.
Is the mud any clearer now?

[Catfish Jac]

It's all conservation of momentum, conservation of energy!

(at least that's what I heard somewhere)

JAC

[reedlv]

The trailer IS being pulled towards the vehicle, at all times. Even though is relative position never changes, if the force is removed, it will no longer stay with the vehicle.
Is the mud any clearer now?[/QUOTE]


Now I am even further confused??? How can the trailer be pulled toward the vehicle at all times???? I though we said it was already hooked to the ball???

[Randy]

In my redneck mentality, I always thought we wuz towing, but now thinking about it, it seems the force is making contact at the ball and the trailer coupling, thus the ball is applying force pushing the trailer in a forward motion.
Now, I don't kow how to factor in global warming, ozone conditions, or x plus y = z, or relative motion stuff, anyways I always thought relative motion was when they left after dinner..

We may be onto something, safety push chains, pushing lights on a trailer, who knows.

[croxt]

Mikechell....

the scientific definition of force is mass times acceleration.

the scientific definition of pressure is a force acting on an area.......not exactly equal to force.

The Lee Trevino definition of pressure....making a $2 bet on a putt with only a $1 in your pocket.....

[reedlv]

Now that is what I call pressure. And Force would be the result of missing the PUTT.

[tylerdan]

If you ever figure this out, let me know. Untill then , just be sure to hook the trailer to the ball or it will not follow you!

[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".