Wacko qusetion

[Danr55]

Actually it.would not.be perpendicular to either line. It would form.an isosceles.triangle.

[Bernica]

If I followed all of Patrick's advice, I would have twin roll bars, a solid flat tappet cam and live somewhere cold and lonely!

[patrickt]

Originally Posted by Bernica

If I followed all of Patrick's advice, I would have twin roll bars, a solid flat tappet cam and live somewhere cold and lonely!

No, you would be healthier, wealthier, and wiser.... And you know that.

[Car Nut]

What if points A B and C were all along the same line and the line goes left to right. Then you move point A to the left (along this line). Think about it.

[Bernica]

Ok, but what if ABC were in space where there is no up/down or left/right?

[Bernica]

Sorry, that was a stupid question on my part in retrospect.
I can only really relate in construction terms, which I think is what Car Nut was leading to.
"If I have my surveyor's transit over point A, and I'm looking at Joe, who is holding the target at point B, and in between I have Patrick holding target C, which is directly in line with my sight of Joe, then I move my instrument to get back to my direct line of sight with Joe. Now, how much do I tell Joe to move over to get Patrick back in my direct line of sight?" Hey, I'm tryin'!

[Bernica]

BTW, "Joe" is actually Mike, but he was working a side-job for cash and Patrick was getting pissy because he wasn't allowed to move to get back in the direct-line shot between Mike and I.

[Danr55]

If you have your transit looking at target B. Target C would be at some point beyond B. When you.move A you change so that line.A B no.longer points directly at.point C.

[Bernica]

Point taken. Thank you Dan.

[Car Nut]

Originally Posted by Danr55

If you have your transit looking at target B. Target C would be at some point beyond B. When you.move A you change so that line.A B no.longer points directly at.point C.

But what if a or b moves along the line towards or away from you.

[Danr55]

Then the intercept line would get longer or shorter depending on which one moves and which way it goes.

[Car Nut]

Everyone is sober, so they all walk a straight line.

[twobjshelbys]

It's a high school trig problem. Originally ABC were on a line. A' is 1/8' (we assume at a right angle to the original ABC line. If A' is 1/8" along the original ABC line then B does not move. No matter what we need to know the angle of A' vs the original ABC line.

Then the new line is A'C. The problem to be solved is the location of B' (where the new line is A'B'C.

It ought the be a solution for a right angle triangle.

But we need to know the precise location of A' first.

If this is a theoretical problem where all of them are zero dimensioned points there will be an answer. if this is a practical problem then just overdrill the f'n hole at B' and get over it. A bolt and washer washer will cover it.


If you need an engineer stamped drawing find a PE.

[Bernica]

Originally Posted by Car Nut

But what if a or b moves along the line towards or away from you.

From me? Or from a stated point?? That wouldn't matter, would it? Because AB are a constant straight line. They could be in motion and will always retain a straight line.

And please don't tell me I have to factor in the curvature of the earth!

I'm just a dumb-ass carpenter, but I'll keep playing

[Mr Jody]

Originally Posted by mikiec

Point A to Point B = 26 inches. Point C is a fixed point in the distance.
If I move point A 1/8" to the left. How much do I have to move point B to maintain a straight line to point C?

The answer is 0".
It’s a trick question….sort of. The trick is in how you look at it.
You have to look at it as if line ABC goes from left to right. Originally, it’s 26” from A to B, and we’ll say X” from B to C, with point C being “in the distance” to the right. Something like this:
A_________________B_________________________C

After moving point A 1/8” to the left, they are all still in that same straight line ABC going from left to right. It's just that now it is 26 1/8” between A and B, and still X" between B and C. No point ever moved out of this line. Now it looks something like this (not to scale...and my attempt at a depiction just shifted B and C to the right, but you get the picture):
A_______________________B_________________________ C

[Danr55]

it could be interpreted that way but the implication is that A moved off the line A B C to the left and created lines A C and B C. The question is asked about the length of the intercept. If there is no intercept, it becomes an invalid question and I've known Mikie long enough to realize he would not ask invalid questions.

Please Mikie, say it isn't so!

[mikiec]

It ain't so.

When A is moved, How far should B move, in the same direction as A, to maintain a straight line to C which does not move.

[Mike Brasfield]

If I were a moderator I would take this post off line.

[Car Nut]

Originally Posted by Danr55

it could be interpreted that way but the implication is that A moved off the line A B C to the left and created lines A C and B C. The question is asked about the length of the intercept. If there is no intercept, it becomes an invalid question and I've known Mikie long enough to realize he would not ask invalid questions.

Please Mikie, say it isn't so!

At what angle from the straight line did A move away from its original point? You appear to have made an assumption that it is 90 degrees, where the "question" does not specify.

[Danr55]

The question indicates that the point A moved 1/8" from line A B C. In order to be 1/8" from the line, it must be in a perpendicular direction. If you move 1/8" in anything other than 90 degrees direction , the resultant distance from line A B C to the relocated point A will be less than 1/8".