On Thu, 11 Dec 2003 13:46:15 -0800, "Rod McInnis"
wrote:


"Steven Shelikoff" wrote in message
...


I'll define a problem

Can I play too??????

Did you ever see the movie "My Cousin Vinnie" when Vinnie is questioning
the old black woman with thick glasses and asks her how many fingers
he's holding up, and the Judge gives her the answer?

[answers snipped]

Did I get it right? Huh? Huh? Huh?
Do I get a star on my paper?????

I'm not gonna tell you. Karen and Basskisser could always come up with
something different.

I will tell you something about the bonus question that may burn your
britches a little: It's sort of a trick question because I didn't
specify that the parts that move when you move the axle are balanced
fore and aft. I *really* didn't think anyone would pick up on that
though.

But for Karen and Basskisser, when you work the problem out, you can
assume that the axle assembly is balanced.

Steve

(Steven Shelikoff) wrote in message ...
On 11 Dec 2003 10:42:43 -0800, (basskisser) wrote:

(Steven Shelikoff) wrote in message ...
On 11 Dec 2003 04:35:05 -0800, (basskisser) wrote:

(Steven Shelikoff) wrote in message ...
On 10 Dec 2003 09:00:31 -0800, (basskisser) wrote:

K Smith wrote in message ...
Snafu wrote:
Gary, I'm not understanding the part about "the longer the tongue, the
furthur back we can put the wheels." To maintain the ~10% of the weight on
the hitch rule, increasing the tongue length works the opposite way.

Absolutely the longer the tongue (drawbar?) the further "forward" the
wheels will by to keep the balance right.

K

Once again, you've proven you stick your nose where it doesn't belong.
You certainly don't understand simple physics. If you make the tongue
longer, you will need to move the wheels BACK to keep the balance the
same. Say you have the tongue 10' from the wheels, and the tongue
weight is 100 pounds, to say, at that 10', you need to resist 100
pounds to lift the tongue. Now, we extend the tongue, to 15'. Now you
have a longer lever, thereby LESS tongue weight. To compensate, you
need to move the wheels BACK.

Tell ya what I'll do, I'm not going to give you the answer, but I'll
define a problem and let basskisser and Karen come up with solutions and
see if they come up with the same one, and then hack out their
differences.

Let's go with the situation above. Assume you have a trailer where the
distance from hitch to axle is 10' and the tongue weight is 100lbs.
Also, assume that the trailer is level because if it isn't, it will
affect the answer. Also assume that the tongue extension has a constant
weight per unit length.

Now increase the length of the tongue to 15' from axle to hitch. Just
from the difference in leverage, what is the new, lower weight on the
hitch?

Since we assumed that the extension has a linear weight/length, the
center of mass of the extension is 2.5' from the hitch and 12.5' from
the axle. So what percentage of the weight of the extension is
supported by the hitch?

Knowing the percentage of the weight of the extension that's supported
by the hitch, how much does the extension have to weigh to exactly
counteract the decrease in weight due to leverage and keep the weight on
the hitch at 100lbs?

If the extension weighs any more than the answer you come up with, then
you have to move the wheels forward to keep the weight 100lbs. Any
less, then you have to move the wheels back.

Bonus question: assume that the original level trailer with the 10' from
axle to hitch weighs 1000lbs and the hitch weight is 100lbs, or 10% of
the trailer weight. You extend the tongue by 5' using an extension that
weighs 10 lbs/ft. How far and in what direction do you have to move the
axle to keep the hitch weight 10% of the new trailer weight?

Have fun!

Steve

I know damn well what the outcome is. But, I don't have to show/prove
to you a damned thing. I solve baby **** like that on a daily basis.

Apparently not if you think that the extension has to weigh the same per
unit length as the boat and trailer to balance it out.

didn't say that. Read for context, please.

When I said that it's possible that you could be wrong, that the wheels
would have to move forward to balance out the extra weight of the hitch,
you said:
The tongue would have to be made out of something VERY heavy, lead
perhaps, to to make up for the additional lever arm from the fulcrum
point. Basically, a foot of tongue would have to weigh the same as a
foot of the boat and trailer.

If you didn't mean that a foot of the extension would have to weight the
same as a foot of the boat and trailer with your statement above, then
what did you mean?

It's called vector mechanics, there Steve.

Instead of thinking you know what the outcome is, why don't you solve
the problem and see if you're right? Don't even worry about the bonus
question if that's too hard. The main question is fairly simple to
solve even with the most basic high school level of physics. Hell, I
pretty much set the whole thing out for you on how to solve it.

Steve

I KNOW I'm right. And, yes, as I've stated, it IS basic high school
physics. Again, I KNOW the answer, but alas, I'm not about to play

You were wrong once, so apparently you don't KNOW the answer.

your idiotic games. I have nothing that I need to prove to an
ignoramus like you. Explaining and teaching something to a dimwit is
all but impossible.

You said it, not me.

Did you figure out where you are wrong in your analysis? Another
hint... You completely left out the fact that the fulcrum is NOT at
the CG in the Z direction.

(Steven Shelikoff) wrote in message
But for Karen and Basskisser, when you work the problem out, you can
assume that the axle assembly is balanced.

Steve

bwaaahaaaa!!!!! You idiot!!!!

(Steven Shelikoff) wrote in message
Are you actually trying to say that if I have a boat/trailer that weighs
10,000 lbs and the hitch is 10' from the axle and the hitch weight is
1lb, then I add an extension on the end of the tongue to increase the
hitch to axle distance to 15' and the hitch extension weighs a million
pounds, that I have not changed the location of the cg of the
boat/trailer in relation to the fulcrum, which is the axle?

Yep, if you are not including the hitch in the calculations, then yes.
What YOU seem to have not included, which would make YOUR analysis
fatally flawed, is the fact that the fulcrum point is NOT the CG, and
ADDITIONALLY, you've done NOTHING about the fact that the fulcrum is a
long ways from the CG in the Z direction.

If that's what you're trying to say, then I can only reiterate my
original point, which is that it's amazing to me the lack of
understanding of simple physics from quite a few posters that this
thread has brought to light.

Steve

I agree. You don't have a clue.

On 12 Dec 2003 04:26:12 -0800, (basskisser) wrote:

(Steven Shelikoff) wrote in message
Are you actually trying to say that if I have a boat/trailer that weighs
10,000 lbs and the hitch is 10' from the axle and the hitch weight is
1lb, then I add an extension on the end of the tongue to increase the
hitch to axle distance to 15' and the hitch extension weighs a million
pounds, that I have not changed the location of the cg of the
boat/trailer in relation to the fulcrum, which is the axle?

Yep, if you are not including the hitch in the calculations, then yes.
What YOU seem to have not included, which would make YOUR analysis
fatally flawed, is the fact that the fulcrum point is NOT the CG, and

Of course not. As I said above, the fulcrum is the axle. The CG has to
be forward of the fulcrum for the hitch to weigh above 0. So now that
you understand that the fulcrum is at the axle and the CG is not at the
fulcrum, I'll ask you again:

When I said:
Bzzzzt! Wrong answer. It doesn't matter what a foot of the boat and
trailer weigh. The fact that it's wrong can be demonstrated very simply
by taking the problem to an extreme. Say in your example above that
your boat and trailer weighs 10,000 lbs and it's balanced so that the
hitch weight is only 1 lb. If you add 5' to the tongue, you are almost
gauranteed to *increase* the hitch weight unless you use some sort of
space aged material that weighs less then 1lb for the entire extension.

The boat and trailer could weight 1000 lbs/foot and you still would
significantly increase the hitch weight if the extension only weighed 1
lb/foot.

and you replied:
Uh, no...let's see if YOU want to play the game. Find in the above
where you are in HUGE error. Hint: The c.g. of the boat/trailer has
not changed in relation to the fulcrum.

Are you actually trying to say that if I have a boat/trailer that weighs
10,000 lbs and the hitch is 10' from the axle and the hitch weight is
1lb, then I add an extension on the end of the tongue to increase the
hitch to axle distance to 15' and the hitch extension weighs a million
pounds, that I have not changed the location of the cg of the
boat/trailer in relation to the fulcrum?

ADDITIONALLY, you've done NOTHING about the fact that the fulcrum is a
long ways from the CG in the Z direction.

Assume that the trailer is level. If the trailer is level, the Z
direction of the CG contributes absolutely nothing to the weight/balance
of the hitch vs. the wheels.

If you notice in the problem I gave you and Karen, I specified that the
trailer is level. So it doesn't matter where the cg is in the Z
direction.

Steve

On 12 Dec 2003 04:21:15 -0800, (basskisser) wrote:

(Steven Shelikoff) wrote in message ...
On 11 Dec 2003 10:42:43 -0800, (basskisser) wrote:

(Steven Shelikoff) wrote in message ...
On 11 Dec 2003 04:35:05 -0800, (basskisser) wrote:

(Steven Shelikoff) wrote in message ...
On 10 Dec 2003 09:00:31 -0800, (basskisser) wrote:

K Smith wrote in message ...
Snafu wrote:
Gary, I'm not understanding the part about "the longer the tongue, the
furthur back we can put the wheels." To maintain the ~10% of the weight on
the hitch rule, increasing the tongue length works the opposite way.

Absolutely the longer the tongue (drawbar?) the further "forward" the
wheels will by to keep the balance right.

K

Once again, you've proven you stick your nose where it doesn't belong.
You certainly don't understand simple physics. If you make the tongue
longer, you will need to move the wheels BACK to keep the balance the
same. Say you have the tongue 10' from the wheels, and the tongue
weight is 100 pounds, to say, at that 10', you need to resist 100
pounds to lift the tongue. Now, we extend the tongue, to 15'. Now you
have a longer lever, thereby LESS tongue weight. To compensate, you
need to move the wheels BACK.

Tell ya what I'll do, I'm not going to give you the answer, but I'll
define a problem and let basskisser and Karen come up with solutions and
see if they come up with the same one, and then hack out their
differences.

Let's go with the situation above. Assume you have a trailer where the
distance from hitch to axle is 10' and the tongue weight is 100lbs.
Also, assume that the trailer is level because if it isn't, it will
affect the answer. Also assume that the tongue extension has a constant
weight per unit length.

Now increase the length of the tongue to 15' from axle to hitch. Just
from the difference in leverage, what is the new, lower weight on the
hitch?

Since we assumed that the extension has a linear weight/length, the
center of mass of the extension is 2.5' from the hitch and 12.5' from
the axle. So what percentage of the weight of the extension is
supported by the hitch?

Knowing the percentage of the weight of the extension that's supported
by the hitch, how much does the extension have to weigh to exactly
counteract the decrease in weight due to leverage and keep the weight on
the hitch at 100lbs?

If the extension weighs any more than the answer you come up with, then
you have to move the wheels forward to keep the weight 100lbs. Any
less, then you have to move the wheels back.

Bonus question: assume that the original level trailer with the 10' from
axle to hitch weighs 1000lbs and the hitch weight is 100lbs, or 10% of
the trailer weight. You extend the tongue by 5' using an extension that
weighs 10 lbs/ft. How far and in what direction do you have to move the
axle to keep the hitch weight 10% of the new trailer weight?

Have fun!

Steve

I know damn well what the outcome is. But, I don't have to show/prove
to you a damned thing. I solve baby **** like that on a daily basis.

Apparently not if you think that the extension has to weigh the same per
unit length as the boat and trailer to balance it out.

didn't say that. Read for context, please.

When I said that it's possible that you could be wrong, that the wheels
would have to move forward to balance out the extra weight of the hitch,
you said:
The tongue would have to be made out of something VERY heavy, lead
perhaps, to to make up for the additional lever arm from the fulcrum
point. Basically, a foot of tongue would have to weigh the same as a
foot of the boat and trailer.

If you didn't mean that a foot of the extension would have to weight the
same as a foot of the boat and trailer with your statement above, then
what did you mean?

It's called vector mechanics, there Steve.

Is that what you meant when you said that to balance out the weight of
adding length to the tongue that a foot of the tongue would have to
weigh the same as a foot of the boat and trailer: "It's called vector
mechanics"? You really don't comprehend english very well, do you?

Instead of thinking you know what the outcome is, why don't you solve
the problem and see if you're right? Don't even worry about the bonus
question if that's too hard. The main question is fairly simple to
solve even with the most basic high school level of physics. Hell, I
pretty much set the whole thing out for you on how to solve it.

Steve

I KNOW I'm right. And, yes, as I've stated, it IS basic high school
physics. Again, I KNOW the answer, but alas, I'm not about to play

You were wrong once, so apparently you don't KNOW the answer.

your idiotic games. I have nothing that I need to prove to an
ignoramus like you. Explaining and teaching something to a dimwit is
all but impossible.

You said it, not me.

Did you figure out where you are wrong in your analysis? Another
hint... You completely left out the fact that the fulcrum is NOT at
the CG in the Z direction.

I guess you haven't figured out that, in the problem where I said "Also,
assume that the trailer is level because if it isn't, it will affect the
answer." I've taken into account the fact that the fulcrum is not at the
CG in the Z direction. So you're wrong above where you claim I left out
that fact.

I would have thought someone as knowledgeable as you claim to be in high
school physics would have picked up on the fact that if the trailer is
level, the Z offset between the fulcrum and the CG contributes
absolutely nothing to the weight/balance between the hitch and wheels
and you can solve the problem without knowing what that offset is.

You also obviously lied when you originally claimed to KNOW the
answer... especially now that you've revealed that you (incorrectly)
think the problem is flawed and has no answer.

Keep digging yourself in deeper. lol

Steve

On 12 Dec 2003 04:22:35 -0800, (basskisser) wrote:

(Steven Shelikoff) wrote in message
But for Karen and Basskisser, when you work the problem out, you can
assume that the axle assembly is balanced.

bwaaahaaaa!!!!! You idiot!!!!

I must have missed something... is this more proof that English is your
second language and you don't know what the meaning of "idiot" is?

I have to ask, how does the fact that you can't solve the problem and
you don't have an understanding of simple high school physics and every
attempt you've made to actually state something about the problem has
been wrong... make me an idiot?

Or are you calling me an idiot because you didn't pick up on the fact
that in the bonus question, the balance of the axle assembly would
affect how for you have to move it and that to solve the bonus question
you have to assume that the axle assembly is balanced fore and aft?
Don't worry, I didn't expect anyone to pick up on that.

You haven't even shown the ability to solve the very simple basic
question. You should really do that before you attempt to understand
the bonus question.

Would you call yourself an idiot because, in trying to find a flaw with
the original problem, you said that I ignored the affect of the Z offset
between the CG and the fulcrum when in fact, I didn't ignore it at all?
Everything you need to solve the problem is there, and you just can't do
it. Every attempt you've made to show how smart you are has backfired.
This is getting to be very commonplace with you.

You were wrong when you said that the problem is flawed because I
"completely left out the fact that the fulcrum is NOT at the CG in the Z
direction."

You were wrong when you said that to keep the hitch weight the same when
adding an extension to the tongue "a foot of tongue would have to weigh
the same as a foot of the boat and trailer."

Care to say something else and make a fool of yourself?

Steve

(Steven Shelikoff) wrote in message ...
On 12 Dec 2003 04:22:35 -0800, (basskisser) wrote:

(Steven Shelikoff) wrote in message
But for Karen and Basskisser, when you work the problem out, you can
assume that the axle assembly is balanced.

bwaaahaaaa!!!!! You idiot!!!!

I must have missed something... is this more proof that English is your
second language and you don't know what the meaning of "idiot" is?

I have to ask, how does the fact that you can't solve the problem and
you don't have an understanding of simple high school physics and every
attempt you've made to actually state something about the problem has
been wrong... make me an idiot?

Or are you calling me an idiot because you didn't pick up on the fact
that in the bonus question, the balance of the axle assembly would
affect how for you have to move it and that to solve the bonus question
you have to assume that the axle assembly is balanced fore and aft?
Don't worry, I didn't expect anyone to pick up on that.

You haven't even shown the ability to solve the very simple basic
question. You should really do that before you attempt to understand
the bonus question.

Would you call yourself an idiot because, in trying to find a flaw with
the original problem, you said that I ignored the affect of the Z offset
between the CG and the fulcrum when in fact, I didn't ignore it at all?
Everything you need to solve the problem is there, and you just can't do
it. Every attempt you've made to show how smart you are has backfired.
This is getting to be very commonplace with you.

You were wrong when you said that the problem is flawed because I
"completely left out the fact that the fulcrum is NOT at the CG in the Z
direction."

You were wrong when you said that to keep the hitch weight the same when
adding an extension to the tongue "a foot of tongue would have to weigh
the same as a foot of the boat and trailer."

Care to say something else and make a fool of yourself?

Steve

again, I KNOW what the outcome is, I know damned well how to solve it,
I do vector mechanics on a daily basis. Please show where you've
factored in vectors for the fulcrum at the CG in the zed axis.

"Steven Shelikoff" wrote in message
...

I will tell you something about the bonus question that may burn your
britches a little: It's sort of a trick question because I didn't
specify that the parts that move when you move the axle are balanced
fore and aft. I *really* didn't think anyone would pick up on that
though.

I thought of that, actually. Should have stated it as an assumption. Seems
like a reasonable simplification to make. If it is a leaf spring suspension
system (not necessarialy a safe assumption) then the axel should be mounted
roughly in the middle of the spring. One end of the spring has a slightly
different mount, but the difference in weight would be small and it would
only have a foot or so of moment arm. The error would probably be lost in
the round off to a single decimal place.

Rod

"basskisser" wrote in message
om...


Yep, if you are not including the hitch in the calculations,

By "hitch" do you mean the draw bar portion that is rigidly mounted to the
tow vehicle, the actual ball joint, or the tongue assembly that is a rigid
part of the trailer?

Steves primary argument here is that you must consider the added weight of
the tongue extension. Please explain what your statement is inferring.

then yes.
What YOU seem to have not included, which would make YOUR analysis
fatally flawed, is the fact that the fulcrum point is NOT the CG,

Huh???

If the fulcrum point was at the center of gravity then the trailer would be
in perfect balance, I.E., no tongue weight.

and
ADDITIONALLY, you've done NOTHING about the fact that the fulcrum is a
long ways from the CG in the Z direction.

First off, if you are going to make this a multi-demensional problem, it
would be more accurate to refer to the "center of mass" instead of "center
of gravity".

All the discussions thus far have been a static problem."Static" is any
constant velocity situation. Note that Steve already defined a "given" as
the trailer was level, so for the purpose of discussion ignore going up or
down hills. As such, the Z axis is not a factor in the equations. The
center of mass will be somewhere above the center of gravity.

If you want to turn it into a dynamics problem then things get a bit more
complicated. Determining how the tongue weight will vary in an accelerated
frame of reference would require knowing where the center of mass is with
respect to the axel and hitch (ball joint). While you are at it, you might
as well consider the third dimension as well: if the "X" axis is for-aft,
the "Z" axis is up-down, then the "Y" axis is across the beam. If the
center of mass is not on the center line of the hitch then there will be a
moment about the hitch when the rig accelerates.

But that is irrelevant for the discussion at hand, which was limited to the
statics problem, which is pretty much a simple textbook exercise. If you
want to turn this into a full blown engineering project, give us the
necessary information and we can analyze it and tell you how the rig will
respond. But before you do that, why don't you demonstrate that you can do
the simple problem first?

Rod McInnis