Welcome to
Science a GoGo's
Discussion Forums
Please keep your postings on-topic or they will be moved to a galaxy far, far away.
Your use of this forum indicates your agreement to our terms of use.
So that we remain spam-free, please note that all posts by new users are moderated.


The Forums
General Science Talk        Not-Quite-Science        Climate Change Discussion        Physics Forum        Science Fiction

Who's Online Now
0 members (), 181 guests, and 2 robots.
Key: Admin, Global Mod, Mod
Latest Posts
Top Posters(30 Days)
Previous Thread
Next Thread
Print Thread
Page 5 of 10 1 2 3 4 5 6 7 9 10
Joined: Mar 2010
Posts: 1,100
K
Megastar
Offline
Megastar
K
Joined: Mar 2010
Posts: 1,100
Quote:

starting at 270 degrees the linear force would be
very small , then at 180 degrees the linear force would
be very large then at 90 degrees the linear force would be very small again.


You can quantify "very small" using trig as in this picture. I might have measured my angles from a different direction to you but it doesn't really matter.


Oh, what I call "longitudinal" I think is what you call "linear". The component of the force parallel to the direction the pipe moves.

Last edited by kallog; 07/10/10 03:04 PM.
.
Joined: Mar 2010
Posts: 1,100
K
Megastar
Offline
Megastar
K
Joined: Mar 2010
Posts: 1,100
Originally Posted By: paul

I believe if I use a 180 degree turn I can divide the
1 second by 180 , since the mass is traveling in a circular path I can use the linear angle and the fc angle to find the amount of linear force for each degree of rotation , then add up the forces as I said before.

Sound like a plan. I've added them all up as you suggest using a spreadsheet instead of a questionable simplification.

I used the equation in my previous message:
F_longitudinal = F_outward * cos(theta)

You can see that with coarse 10 degree steps it isn't quite 8000N, but the smaller the steps the more it approaches 8000N.

Joined: Mar 2006
Posts: 4,136
P
paul Offline OP
Megastar
OP Offline
Megastar
P
Joined: Mar 2006
Posts: 4,136
looks right to me , pretty good excellmanship also.
that is exactly what a spring would do , a spring
would be compressed by the mass slowing the pipe to a stop.

if the spring stops the mass in 0.5 seconds it requires 8000N
to do that , it then has 8000N stored force to push the mass
away again accelerating the pipe in the opposite direction.

if the spring stops the mass in 1 second , it requires 4000N
to do that , but that would only slow the pipe down , it then
has 4000N stored to push the mass away with stopping the pipe.

so if the turn is increased in lenght to 80 meters the
pipe would stop , and the mass would still have a speed of 40 m/s when it exits the turn.

correct?

I think you had also mentioned that earlier.
so you were right about that.




3/4 inch of dust build up on the moon in 4.527 billion years,LOL and QM is fantasy science.
Joined: Mar 2010
Posts: 1,100
K
Megastar
Offline
Megastar
K
Joined: Mar 2010
Posts: 1,100
Originally Posted By: paul

if the spring stops the mass in 0.5 seconds it requires 8000N
to do that , it then has 8000N stored force to push the mass
away again accelerating the pipe in the opposite direction.

Indeed. If 'opposite direction' means opposite to the direction the accelerator started moving the pipe in

Quote:

so if the turn is increased in lenght to 80 meters the
pipe would stop , and the mass would still have a speed of 40 m/s when it exits the turn.


Careful, all these variables aren't independent of each other. Since it's twice as long, the mass now spends 2s in the turnaround, so the overall effect is half the force applied for twice as long.

When I earlier worked out that the pipe would reverse direction, I was using a 1s turnaround. With a 2s turnaround it only needs half the force to achieve the same result.

Joined: Mar 2006
Posts: 4,136
P
paul Offline OP
Megastar
OP Offline
Megastar
P
Joined: Mar 2006
Posts: 4,136
I think I will make a program to figure this out for me.

I tried several times but theres always something wrong.

so give me a few hours perhaps.


3/4 inch of dust build up on the moon in 4.527 billion years,LOL and QM is fantasy science.
Joined: Mar 2006
Posts: 4,136
P
paul Offline OP
Megastar
OP Offline
Megastar
P
Joined: Mar 2006
Posts: 4,136
well , I couldnt get the force to lower , so
I suppose that the design needs to change.
the lenght and time of the turn never affected the total force applied.

so it needs a opposing accelerator to work.

the two turns cancel each other out.
-8000N
+8000N

so the +4000N from the acceleration is all that is left.

if 2 accelerators are used
and they are timed so that one mass
enters its second turn as the other mass enters its first turn then these will cancel each other out.

so its now a matter of timming these two masses.

if they are in seperate loops then they should
syncronize with each other.

perhaps instead of accelerating the masses at 5m/s/s the
acceleration could be slowly increased from 0 m/s/s
this can be controlled by the amount of electricity used
to accelerate the masses in the accelerators.

this can help to time the masses also.

now if you had 120 accelerators , every second there would be 2 masses begining acceleration , and this would greatly smooth out the ride.

but we should start with two accelerators first.
we already know what happens when only 1 is used.









3/4 inch of dust build up on the moon in 4.527 billion years,LOL and QM is fantasy science.
Joined: Mar 2010
Posts: 1,100
K
Megastar
Offline
Megastar
K
Joined: Mar 2010
Posts: 1,100
Originally Posted By: paul
well , I couldnt get the force to lower , so
I suppose that the design needs to change.
the lenght and time of the turn never affected the total force applied.

Really? If the turnaround was longer, the radius would be larger, causing a reduced centrifugal force.

Quote:

the two turns cancel each other out.
-8000N
+8000N

If they're being used simultaneously.


Quote:

so its now a matter of timming these two masses.

Not sure where the 2nd acccelerator would go ?? But I don't think it's possible to keep them synchronized -

Suppose both masses enter and exit their opposite turnarounds at the same time and with the same speed.

The mass that went through the 1st turn floats to the 2nd turn. But the mass that's gone through the 2nd turn is then accelerated and reaches its 1st turn sooner. They're now out of sync.

Joined: Mar 2006
Posts: 4,136
P
paul Offline OP
Megastar
OP Offline
Megastar
P
Joined: Mar 2006
Posts: 4,136
I let the program figure it out , I increased the
lenght of the turn , then got the radius for that lenght.

then used the v^2/r*mass to get the force.

then I used your excell results and divided the
result by 1.57956307021181 which was taken from
your 12k / 7k results.

it always showed a total of 12k for total force when
time was included.

but the cf did decrease for each meter of lenght I used.

cf * time = always 12,566
and the total linear force was always the same
12,566 / 1.5795 = always 7955.599

it probably will be extremely hard to get syncronization
because if you increased mass velocity you get increased force through the turns.

I think the answer is somewhere in numbers.










3/4 inch of dust build up on the moon in 4.527 billion years,LOL and QM is fantasy science.
Joined: Mar 2010
Posts: 1,100
K
Megastar
Offline
Megastar
K
Joined: Mar 2010
Posts: 1,100
Originally Posted By: paul

cf * time = always 12,566
and the total linear force was always the same
12,566 / 1.5795 = always 7955.599


Hehe, at risk of being an 'I told you so'. Remember I used to keep saying the impulse applied to the pipe is always of magnitude 8000Ns regardless of how long the mass spends turning around, or how much force it applies? That's exactly what your unchanging result is, that same old impulse.

Joined: Mar 2006
Posts: 4,136
P
paul Offline OP
Megastar
OP Offline
Megastar
P
Joined: Mar 2006
Posts: 4,136
OK , rub it in...

LOL.

I still cant exactly see how 8000N can be directed in the
(-) direction from a 12000N force , that only leaves 4000N
dispersed in the lateral directions.

are you sure that you used the correct equation?


3/4 inch of dust build up on the moon in 4.527 billion years,LOL and QM is fantasy science.
Joined: Mar 2010
Posts: 1,100
K
Megastar
Offline
Megastar
K
Joined: Mar 2010
Posts: 1,100
Originally Posted By: paul
OK , rub it in...


Alright, if you insist, my favorite paragraph :P ..

as far as I am concerned I have won this discussion because
of my use of non - fictional forces and numbers , you have done nothing but try to use fictional forces and went as far as adding up those fictional forces to arrive at fictional numbers.



Quote:

I still cant exactly see how 8000N can be directed in the
(-) direction from a 12000N force , that only leaves 4000N
dispersed in the lateral directions.


I can't quite visualize it very well. Tho there isn't really 'more' longitudinal force than lateral. Tho the entirety of the average force is longitudinal, and none lateral.

If you took just one of the two quarter-turns, it'd have the same 8000N average force in both directions. So the total average force would be directed at 45 degrees. When you also average that with the other quarter-turn, the two opposite lateral components average to zero, leaving only the two 8000N longitudinal components, which average to 8000N.

If that makes any sense at all :P

Last edited by kallog; 07/10/10 09:48 PM.
Joined: Mar 2010
Posts: 1,100
K
Megastar
Offline
Megastar
K
Joined: Mar 2010
Posts: 1,100
This might be illuminating somehow

pi/2 = 1.5708

pi/2 * 8000 = 12566

!

Joined: Mar 2006
Posts: 4,136
P
paul Offline OP
Megastar
OP Offline
Megastar
P
Joined: Mar 2006
Posts: 4,136
when you think about it as being a spring it makes
complete sence , 4000 in 4000 out

I think I have found a way to send most of the
(-) force lateraly.

using springs that are compressed lateraly.

I will need to brush up on that first.

think of the turn being mounted on a moveable track.
the turn has 4 arms that extend backward at a 45 degree angle to 4 springs
the 4 springs are mounted lateraly , the mass enters the turn , the force pushes the mount backward this compresses the 4 springs , most of the force is absorbed
lateraly by the 4 springs.

the springs then push the turn forward again sending the mass forward , the turn might need to be just a half turn
or the turn can be removed.

and this is also done lateraly , so most of the force is absorbed and expended lateraly by the 4 springs slowing stopping and accelerating the mass.

what do you think?

oh and you can use the accelerator to accelerate the
mass from 40 m/s to 0 m/s and that is also in the
(+) direction , and its ready to go again.

I think weve done it.

and by the way , the mass can generate electricity
while the accelerator is braking it.

this way it wont cost anything to opperate it.

but that would only be in a perfect world scenario
there has got to be some losses somewhere.










3/4 inch of dust build up on the moon in 4.527 billion years,LOL and QM is fantasy science.
Joined: Mar 2010
Posts: 1,100
K
Megastar
Offline
Megastar
K
Joined: Mar 2010
Posts: 1,100
Originally Posted By: paul

the 4 springs , most of the force is absorbed
lateraly by the 4 springs.


It'll collapse unless the springs have enough stiffness in the longitudinal direction. They'll still carry the same load that way. They just might also carry a much higher load laterally as well.

There's no way you can arrange springs to make a component of the force dissapear. Imagine, if there was, you could lift a car with one hand. Just put this 'force redirecter' between you and the car, so its weight is sent sideways.

Quote:

oh and you can use the accelerator to accelerate the
mass from 40 m/s to 0 m/s and that is also in the
(+) direction , and its ready to go again.

Then the mass is stopped so the machine can no longer operate??

Joined: Mar 2006
Posts: 4,136
P
paul Offline OP
Megastar
OP Offline
Megastar
P
Joined: Mar 2006
Posts: 4,136
Quote:
It'll collapse unless the springs have enough stiffness in the longitudinal direction. They'll still carry the same load that way. They just might also carry a much higher load laterally as well.


then you would want to use springs that have enough
stiffness.
they will carry the same load that the 100kg mass * its
speed places on it because it is what the force of the
load is being placed on.

the load begins at a 45 degree angle , and ends at 1 degree angle.

the brunt of the force that is applied is transmitted lateraly into the springs , not in the (-) direction.

this is a common way that engineers use structual design
to make car crashes less strenous on the driver.

springs are used throughout structual engineering and are
in use to reduce stresses.

there will be some force directed in the (-) direction
but most will be directed in the lateral or sideways directions.

like before when the turn was placing 8000N of the 12000N in the (-) direction because the directional forces applied to the turn were not being absorbed by springs and the forces were not being directed outwards.

using the springs directs most of the force outwards
the stress that the pipe feels is outwards.

Quote:
There's no way you can arrange springs to make a component of the force dissapear. Imagine, if there was, you could lift a car with one hand. Just put this 'force redirecter' between you and the car, so its weight is sent sideways.


I can lift a car with 1 hand , all I need is a long lever
and fulcrum or a set of pulleys , the springs do not make any forces dissapear , I know you know that , they do not go away they are stored by the springs , and while the forces are being held by the springs inside the pipe those forces are all sideways.


Quote:
Then the mass is stopped so the machine can no longer operate??


you stop the mass after the springs have tossed it
back into the accelerator.

this removes the free float side.

there are no more turns.

accelerate the mass with the accelerator.(-)40m/s
the springs accelerate the mass to ()0m/s
the springs accelerate the mass to (+)40m/s
the accelerator accelerates the mass to()0m/s

then the mass is setting where it began , it
is waiting to be accelerated again.

this way the mass never travels faster than
40m/s so the springs will always be stiff enough to
stop the mass.

so now its like this.

4000N (+) pipe , as the mass accelerates

low (-/+) force to pipe as springs reverse mass direction

4000N (+) pipe , as accelerator stops the mass.

repeat , each cycle adds acceleration to the pipe.

the magnatude of the (+) pipe velocity will prevent
the low (-) forces from stopping the pipe , the low
(-) forces will slow the pipe , however by directing
the brunt of the (-) forces outwards the (+) forces will
always win a battle between the forces.

may the force be with you.
live long and prosper.

fascinating!









3/4 inch of dust build up on the moon in 4.527 billion years,LOL and QM is fantasy science.
Joined: Mar 2010
Posts: 1,100
K
Megastar
Offline
Megastar
K
Joined: Mar 2010
Posts: 1,100
Originally Posted By: paul

the load begins at a 45 degree angle , and ends at 1 degree angle.

All you're doing is creating extra lateral forces. The average longitudinal force is still 8000N, and the average of the total lateral force of all 4 springs is still 0.

Quote:

this is a common way that engineers use structual design
to make car crashes less strenous on the driver.

No. They reduce the force by increasing the length of time the impulse is applied to the occupants for. You can do that if you want, but it's the same old choice between 8000N for 1s, or 4000N for 2s. Neither gives any advantage.


Quote:

springs are used throughout structual engineering and are
in use to reduce stresses.

Yes. But they also increase the length of time the parts are subject to that reduced stress.


Quote:

using the springs directs most of the force outwards
the stress that the pipe feels is outwards.

True, You're creating extra stress on the pipe walls without reducing the longitudinal force. It's effectively a lever mechanism.


Quote:

I can lift a car with 1 hand , all I need is a long lever
and fulcrum or a set of pulleys , the springs do not make

It's still transmitting force to the ground through the fulcrum/pulleys. The total weight force felt by the ground is no different.

Joined: Mar 2010
Posts: 1,100
K
Megastar
Offline
Megastar
K
Joined: Mar 2010
Posts: 1,100
Just to be clear, this is what you're saying, right?




If you take the machine and put it on scales, with a static mass just sitting there, it'd weigh less?

Joined: Mar 2006
Posts: 4,136
P
paul Offline OP
Megastar
OP Offline
Megastar
P
Joined: Mar 2006
Posts: 4,136
I'll upload a picture of what I'm talking about.
thats not exactly what I have in mind.

I havent tried to figure out the stresses and the direction
that they will be applied or the time , so I cant really say much more for now.

the picture will give a clearer understanding of the spring setup , and the force directions involved.


3/4 inch of dust build up on the moon in 4.527 billion years,LOL and QM is fantasy science.
Joined: Mar 2006
Posts: 4,136
P
paul Offline OP
Megastar
OP Offline
Megastar
P
Joined: Mar 2006
Posts: 4,136
Quote:
No. They reduce the force by increasing the length of time the impulse is applied to the occupants for. You can do that if you want, but it's the same old choice between 8000N for 1s, or 4000N for 2s. Neither gives any advantage.


since Im no longer turning the mass around , the only force
I must overcome is 4000N , the 100kg mass can be accelerated
to 40m/s velocity in 1 second and it will travel a distance of 20 meters in that 1 second.

so stopping the mass requires that exact same force applied in the opposite direction in that same time.

f=ma
4000N = 100/40
a=f/m
40=4000/100

in 1 second the mass stops.

it will not require 8000N
to stop the mass in 20 meters and 1 second

BTW , the springs in your picture arent lateral they are at
a 45 degree angle , so they would direct the force to a 45 degree angle , I said the springs would direct the force in a lateral direction ie...90 degrees from the direction that the 100kg mass is moving.







3/4 inch of dust build up on the moon in 4.527 billion years,LOL and QM is fantasy science.
Joined: Mar 2006
Posts: 4,136
P
paul Offline OP
Megastar
OP Offline
Megastar
P
Joined: Mar 2006
Posts: 4,136
Quote:
If you take the machine and put it on scales, with a static mass just sitting there, it'd weigh less?


wow , weve moved back to the earth?

good thing were not talking about what would happen on earth.

put the scales in space and see what the scales read.


3/4 inch of dust build up on the moon in 4.527 billion years,LOL and QM is fantasy science.
Page 5 of 10 1 2 3 4 5 6 7 9 10

Link Copied to Clipboard
Newest Members
debbieevans, bkhj, jackk, Johnmattison, RacerGT
865 Registered Users
Sponsor

Science a GoGo's Home Page | Terms of Use | Privacy Policy | Contact UsokÂþ»­¾W
Features | News | Books | Physics | Space | Climate Change | Health | Technology | Natural World

Copyright © 1998 - 2016 Science a GoGo and its licensors. All rights reserved.

Powered by UBB.threads™ PHP Forum Software 7.7.5