>most people on this sub think it's 200N

>sub
Fuck off, the scale is broken

The scale isn't symmetric so it will slide to one side.

Unsolvable problem

200 gif newtons

100N i'm high on K and i asked chatgpt

>>16707801 (OP)
if the spring hangs from the ceiling and has a 100 N weight on the hook then the ceiling will exert a counterforce of 100 N on the spring, which is comparable to what is shown here, so 100 N is the answer

>>16707823
try pulling it with both hands

>>16707832
hand me one and I will try

>>16707801 (OP)
>most people that attempt to explain this fail miserably with an equal and opposite cop out

It's true that the scale is experiencing two 100N forces. But how does the scale work? In fact it's experiencing the same forces it would if it were hanging vertically from the roof and had a 100N weight hanging from it. So clearly to the scale this means 100N.

>>16707849
In fact it would realistically read more than 100N, as there is also the vertical force on the scale to consider. The wire must sag slightly in order to support the scale. This means the 100N forces are applied at a slight angle, which may change the reading depending on how the scale is made.

>>16707801 (OP)
it will read 0. 100-100N=0N

It will read sqrt(2)/2*100

People actually this it's 100N?
Fishhook scales are very cheap
Hold it at two ends
Pull on the side that is the hook. It reads a force.
Hold it again at two ends.
Now pull on the opposite side. It reads a force
Hold it again at two ends
Pull on both ends. It reads a higher force.

>>16707881
My brother in christ

Dynamometers measure force by the deformation in a spring. If there were 100 N being applied on only one side of the spring, it wouldnt measure 100N, it would measure 0N (the spring would move, not deform).

>>16707887
Yes obviously the sensor is in the spring
That is not the point. The principle is the how and where the forces are applied
The sensor can detect the other forces via newtons 3rd law
This is such a trivially simple experiment to do yourself

>>16707881
>dude just pull the spring with a force lmao
if you pull with 100 N force on one end you're gonna be pulling with 100 N force on the other end too or the spring don't be stationary

>>16707889
https://physics.stackexchange.com/questions/422142/what-force-does-the-dynamometer-show-in-this-case#422153

>>16707801 (OP)
Like many others said, it's 100N.
Imagine the setup from the OP. Now grab the ring on the right side of the scale, hold it tight, and cut the thread holding up the right weight.
The deformation of the scale won't change throughout this, but it's now connected to one weight and one fixed point (your hand), as if it was just hung from the ceiling.

>>16707898
>>16707881
>>16707849
You fucking retards, if the scale was hanging the tension would have been due the weights scale NOT a whole 100N
If hang by a pull up bar, are you holding your own weight or 5 tons?

Not one of you 100N people have conducted this experiment.
You overrely on your "theory" with no respect to reality

>>16707903
Have you?

>>16707903
I just conducted the experiment and the result was that the spring showed 100 N. Checkmate.

>>16707904
Yes. It was closer to 200N than to 100N.
Not exactly 200N, but around 180N

>>16707907
Pics or it didnt happen

The scale reads in kg not N, checkmate

>>16707801 (OP)
The "problem" is the scale isn't being used as it normally would, which is with one end fixed (e.g., the closed loop end hanging from a hook in the ceiling).
Fix one end: The scale reads 100N (the 100N weight on the right has no effect on the scale).
Fix both ends: The scale reads 0N (neither weight has an effect on the scale).
Leave both ends free: The scale reads 200N (both weights have an effect on the scale).
The last scenario is what's pictured in the diagram.

>>16707914
good bait

>>16707910
We are scientists here. I will outline my methodology so that you may replicate my work.
Tie the end of a fish hook scale to an immobile infinitely heavy bookshelf.
Apply a consistently force on the hook with your fingers.
Do this dozens of independent times for consistency. Switch hands so that you master this muscle-numerical connection.
Do this across multiple days to ensure mastery.
Now, untie the scale from the infinitely massive end.
Grab it from both ends, one with each hand.
Apply with both hands that force you mastered.
The measured force will be a little less than double the original. Not exactly double but much higher than the original.
A picture would not satisfy you. You would assume I have pulled harder when I assure you I have not.

I will await your attempted replication with masterfully baited breath.

Instantly replace the other weight with a wall. The scale starts sliding then stops as the string becomes taut. Now clearly the tension of the string due to wall and the weight must be 100 N.

Should it measure 200 N then?

>>16707924
Again, conduct the experiment. Reality often contradicts theory.

>>16707925
If the spring is more stretched in your experimen then string must be longer. Is this magic string?

>>16707801 (OP)
The spring inside the scale can "freely move" until it reaches the same tension as the weight, 100N, which it will show. The other string could just as well be connected to a wall because it doesn't have to hold more than 100N, which would be the force on the wall too.

>>16707927
You misunderstood the procedure. The string only ever feels one force from one hand.
After it is untied (and removed) you pull. There is no string that is getting elongated.

>>16707948
>The string only ever feels one force from one hand.
stop masturbating

(200+100+0)/3 = 100N. Ez.

>>16707962
Thank you for this. I realize now the correct model to use.
When I said I measured 180N, I see now it was actually 167N. Or at least I suspect.
I will redo my experiment more precisely and many times. Then I will average the results.
I am eager to see if I measure 5/3 the original value.
Clever.

Answer:
a) If this scale is a simple spring (one end connected to the closed loop side, the other to the free-moving hook side) both weights will impart stretch and the scale will read 200N.
b) If the scale is designed just to measure load on the hook (say with a dynamometer) then it will do just that and read 100N. In this case the weight on the right (>= the weight on the left) just serves to hold the scale in place.

>>16708004
>both weights will impart stretch and the scale will read 200N.
wrong, the tension in the spring is 100N, which is what it would show, and wouldn't magically double when one replaces a wall by gravity.

>>16708016
With 100N hung from each end the load on the spring is not 100N, it is 200N.
You haven't magically replaced a wall by gravity, you've doubled the load on the spring by doubling the weight hung from it.

>>16708027
The load on the right opposes the load on the left, just like a wall would. The force that stretches the spring is 100N. No matter how you construct it, the left load will cause an equal opposite force on whatever it's attached to on the right.
The only way to get 200N would be to hang both on one end and attach the other to whatever can pull 200N without moving.

>>16707801 (OP)
it's juan hondred N
when hanging from a ceiling, the ceiling's got to provide the counter force to keep things in static equilibrium. assuming the scale's mass is negligible, then it the only force to counter is that caused by the weight of the object, so the force and counter force are equal and opposite.

in OPs pic, the force that the ceiling must exert to keep things in static equilibrium has been swapped out for an object whose weight is equal to the required counter force needed to keep things in static equilibrium.

>>16707801 (OP)
I was tricked by this problem when I imagined that the weight on the right is infinite. Naturally the spring will immediately be pulled at a great force, so I assumed that the forces are additive. But I think this is only because of acceleration. Imagine a rocket flying upward at a constant rate, with the spring attached to the bottom of the rocket, dangling the weight. Then the spring will still read 100N. Imagine that you yourself are hanging on to the bottom of the rocket. If it’s traveling at a constant rate, then it doesn’t matter how fast it’s going (ignoring air resistance), you will still feel the same amount of tension in your arms as if you were simply hanging from it.

>>16708044
There isn't any need to complicate it like that. Just know that one of the weights is taking the place of a reaction force that would hold it to a wall or hook or something. You can easily see this by drawing a FBD and checking the internal force of one side of the string. The scale reads 100N and anyone saying otherwise is stupid or trolling.

>>16708034
Okay, we have the setup as in OP's pic and the scale is a simple spring.
Add 1N to one side. The spring stretches and the scale reading goes up 1N.
Add 1N to the other side. Again, the spring stretches and the scale reading goes up another 1N.
A total weight of 2N has been added and the scale indicator goes up 2N.
Not according to your argument, however. You would argue after adding 2N of weight (1N to each side) the load on the spring and scale indicator only goes up 1N.

A spring measures a tension of a wire. The tension is 100 N.

>>16708053
>Add 1N to one side. The spring stretches and the scale reading goes up 1N.
No it doesn't, it moves to that side with no stretching, because there's no opposite force, thus no tension.
>Add 1N to the other side
Now it stretches according to F=kx, F being 1N.
>You would argue after adding 2N of weight (1N to each side) the load on the spring and scale indicator only goes up 1N
Yes.

>>16708058
You cite Hooke's Law but it supports neither of your assertions:
1) You argue a free spring under a change in load F' will not change its length (that is, x'=0) if that load is applied asymmetrically to its ends.
2) You argue a free spring under a total load F applied equally to its ends will not displace according to F=kx but instead F/2=kx.
Neither of these is true according to Hooke's Law.

>>16708124
It's little to do with Hooke's Law but with Newton's Laws. You know, you could just admit you were filtered instead of sperging about it.
1) A free spring will move as a rigid body if there is a force pulling it in one, but no force in the other direction. The left load being 1N more than the right results in an accelerating force of 1N on the whole body of (spring + 2 loads).
2) it's not a "total load" but two opposing forces. If those 2 loads were on one side of a spring attached to a wall, it would indeed show 200N, because the wall is pulling with 200N too and so there's 200N worth of tension that deforms the spring until 200N=kx holds.
With 100N pulling on both sides the tension is 100N. It doesn't matter whether the force comes from a load or anything else.

>>16708192
>newtons law
Also
>>16708058
>no opposing force

Pick one.

>>16708193
Yes, if a force accelerates an object it means there's no force cancelling it out. The 3rd law reaction force in this situation is the 1kg load pulling the Earth by gravity.
I know it must feel bad being filtered by elementary mechanics but you don't have to go obtuse full retard about it.

>>16708208
Okay, that was someone else who answered and was rude about it so I'll stop the ruse.
Yes, it's 100N and you're correct it's simple statics.

>>16707837
*Hands you my penis*
Just pull on it for awhile and see what happens

It's funny how confidently wrong people are about basic physics. It's 100N.

>>16708282
>It's 100N
But why though?

>>16708284
There are a number of adequate explanations in this thread. I'm sure the problem has been posted on leddit too, should be easy enough to find.

The correct answer is 0N because no stretching occurs (neither end is a fixed point)

>>16708695
What? The spring is in dynamic equilibrium

>>16708700
but if it is an ideal linear spring then there is no stretching

>>16708282
It's engineering time. I do this all day in school. it's so fun to watch these threads.
>>16708284
where do you disagree?

>>16708284
>But why though?
Scale shows weight pulled on the spring.

>>16709452
Where your analysis fails is that being attached to the other weight is equivalent to a constant rate of acceleration in the wall the device is attached to.
What you're arguing is equivalent to these two statements:
>In the standard use case where the device is hanging from the ceiling, flipping upside down would result in a measurement of 0N.
>If you were holding the device, pulling one end with one hand would measure the same as pulling the ends apart with both hands
Both of these are obviously false.

The correct, non trolling, answer is 200N

>>16709711
>In the standard use case where the device is hanging from the ceiling, flipping upside down would result in a measurement of 0N.
wdym upside down? you mean flipping the scale?
>If you were holding the device, pulling one end with one hand would measure the same as pulling the ends apart with both hands.
you obviously don't get it. probably bait

>>16709720
>wdym upside down? you mean flipping the scale?
Correct.

More importantly, in the example you(?) showed where the scale is held horizontally and attached to a wall, the wall would need to be accelerating away from the scale in order to act the same way as a weight in its place would due to the equivalence principle.

>>16709726
flipping the scale doesn't matter. it will read the same.
let michael explain it to you (timestamp)
https://youtu.be/Xc4xYacTu-E?t=381

you don't get the equivalence priciple. equal and opposite. the wall pulls the same as another weight with 100N. the entiere rope has 100N tension no matter where you measure. The table does acclerate up in curved space time called gravity making a force.

>>16709731
>the entiere rope has 100N tension no matter where you measure
If it has a 100N equivalent force pulling either side, the total tension is 200N.
The equivalence principle is simply that being pulled by gravity is the same as accelerating at an equivalent rate.

>>16709743
>If it has a 100N equivalent force pulling either side, the total tension is 200N.
no
I finally found a real world example that proves you wrong
https://youtu.be/XI7E32BROp0
/thread

>>16709744
Fake news. AI slop.

Okay, yeah. You got me. Tbh my issue was not considering the fact that, if the weights were imbalanced, the scal would end up falling over because I'm dumb.
Well played.

>>16709452
>>16709744
Tie the fucking end to the ground and keep both pulleys when demonstrating your fucking principle, retards. How the fuck is the source of the aneurysm not obvious?

>>16709747
the whole point is that all systems is that all are at an equalibrium. rare sight of someone manning up on this board and admitting they are wrong. 100N tension in the rope is 100N tension no matter where you measure. The only thing that is 200N is the total force of the table down considering nothing has mass but the weights. My body is pushing 800N on the earth the same as the earth is pushing 800N on me. A scale doesn't show 1600N because it just adds them.
>>16709748
tf is you yapping about

>>16709751
Yeah I fully understand now.
I was just pointing out the intuitive point that, if one weight was 100N and the other was 50N, the scale obviously wouldn't read 150N as it's tipping over. That might be easier to get the point across with.

BIG SCIENCE IS LYING TO YOU

>>16709751
>A scale doesn't show 1600N because it just adds them.
For your mom it does

If it's just 100N, then back in ancient times, why did they need two dudes?

>>16710328
More fun.

>>16710328
or 4 horses

>>16709452
>where do you disagree?
Never said I disagree with anything
Just trying to ask if someone can explain it in simple terms other than, " equal tension blah blah quote"

Can anyone explain it in layman's terms?

it's 200 N.
next

Bru, it's 100N, someone literally did the experiment. WTF is wrong with you people?

https://www.youtube.com/watch?v=XI7E32BROp0

>>16707801 (OP)
The force on the scale from the two weights totals 200 N. But the reading is 100 N.

Scales are meant to be used while stationary. I.e while the force holding the scale is equal to the force weighing it down. Doesn’t matter if the force holding the scale is your hand, or a rope attached to a wall, or an object of equal weight.
Use picrel and you will understand.

It's the same as fixing one end of the scale to the wall.
The answer is 100 N.

>>16710359

>>16707801 (OP)
100 Newton units

>implying scales can read

>>16710359
3rd Newton's law.

>>16707801 (OP)
There is 50 N force on the string upwards and 50 N force on the string sideways which means 50 N force is what is keeping the base still. If you had the whole system looped on 1 gear the stress on the string is doubled, if you had half the angle the doubled stress will also halve because if there was no angle the stress would be 0 and both ends would just freefall, so if you add another gear and the angle is halved the stress is 50 N. Then the stress happens from both sides which is 100 N.

>>16707849
I always liked how in this meme pepe is sad on is ID but happy in his lab gear.

It will measure 50 N.

>>16711208
rong >>16709744

what if you hold the scale with your hands?

>>16710328
>>16710351
based knower btfo sci

It will read 99.9999999… Newtons

classic middle school problem

>>16707801 (OP)
The tension force on the scale from the left weight is 100 N (pointing left). The tension force on the scale from the right weight is 100 N (pointing right). Thus, the net force on the scale is zero.

>>16712738
>The tension force on the scale from the left weight is 100 N (pointing left). The tension force on the scale from the right weight is 100 N (pointing right). Thus, the net force on the scale is zero.
Right but that's not the point. The picture asked for the scale wich sees the left weight.

>>16713022
Then the answer is 100 N since only one side of the scale influences the reading.

the tension force on each side of the spring cancels out, so its 0

>>16713048
> Then the answer is 100 N since only one side of the scale influences the reading.
I think so too
>>16713074
>the tension force on each side of the spring cancels out, so its 0
Maybe that's the reason why the scale holds position.

>>16707916
>We are scientists here.
>/sci/
saar...

>>16707801 (OP)
This is a classic physics problem that often trips people up!
Here's the explanation:
The scale (which is a spring scale, like a dynamometer) measures tension in the rope it's attached to.
Imagine if you were holding one end of the rope and someone else was pulling the other end with a force of 100 N. The scale would read 100 N, because that's the tension you're exerting (or experiencing).
In this setup, each 100 N weight creates a 100 N tension in the rope on its respective side. The spring scale is essentially measuring the force being exerted by the rope on the scale from one side.
It's not adding the forces together to get 200 N. Think of it this way: the scale isn't measuring the sum of the two weights; it's measuring the force needed to hold one side of the system in equilibrium. One side pulls with 100 N, and the other side provides the "reaction" force of 100 N to keep the scale stationary.
Therefore, the scale will read 100 N.

>>16707801 (OP)
I don't know how this particular scale works, and you cannot prove it works a certain way, so i make the assumption there's a magical tiny obese man-fairy that looks outside to get a reading and display it, in this situation it decides to fart very loudly and display "OP is a faggot". Given that the problem didn't specify the mechanism, my assumption cannot be discarded.

>>16707801 (OP)
100N because a dynamometer will always experience the double force of what is shown if the dynamometer is stationary.

>>16714036
So you are telling me when I yolk 250 lbs that I am actually a lanklet hitting a 125?

>>16707903
A new 12000 rpm schizo is born

300 N

100 N for each side + a dark force of 100 N

>>16707916
Why didn't you use weights and pulleys instead of this flimsy method?

>>16715581
Dark Springs, Pullys, & Cables?

Its 100 N because there is dark matter of -100 N recoiling the spring

the absolute state of westoid education and those meme SAT tests filled with questions targeted for toddlers. no wonder koreans, japanese and chinese fly to USA/GAYNADA and easily destroy any competition they face. while the timmies cry their eyeballs out and demand public and private institutions for easier test because memorizing is le bad, the asian kids memorize, understand and prove their superior intellect with high scores in tests made for real hard working students such as suneung and gaokao.

>>16716212
of only they weren't such ugly awkward autists with tiny genitalia they would easily dominate the world

>>16707801 (OP)
200N

0N
100N newton to the left gets cancelled out by the 100N on the right

>>16717487
fuck. it's 100N. but the scale wont move regardless

>>16707801 (OP)
construct free body diagram

>>16710328
The difference is that these dudes exert forces which change over time and generally are not equal by modulus. It makes doing that torture with two dudes more efficient than with one.
Both forces in the OP don't change over time. You shouldn't ignore that.

>>16707801 (OP)
It's 100N. If you remove the left weight and hold the scale it will read 0N. Then you start slowly pulling on it and you can reach 100N. Anything over and the left weight will drop and pull the right weight up.

Do most people have trouble imagining things or what?

>>16711812
Sn = 90 + 9 + 0.9 + 0.09 + 0.009 + 0.0009 + 0.00009 + .........
Sn = a/(1-r)
Gn = a*r^(n-1)
a = 90
r = 0.1
Sn = 90/(1-0.1) = 90/0.9 = 900/9 = 100

>>16716212
You retard, the sigma F = 0 is on the fucking weight not the scale

>>16707801 (OP)
You bullshit picture confuses mass (wich is in kg) with force (N), wich is a vector. Further there are no scales this type (except specially noted) that reads in Newton because that is 1.02 times the mass(kg) that a scale of that type supposed to measure.

>>16720646
as a result the scale shows no Newtons (not even Oldtons) wich is mathematical represented with 0 (zero).
So the answer is 0, prove me wrong.