# Tagged Questions

This tag is for the classical concept of forces, i.e. the quantities causing an acceleration of a body. It expands to the strong/electroweak force only insofar as they act comparable to ‘classical’ forces. Use [tag:particle-physics] for decay channels due to forces and [tag:newtonian-mechanics] or ...

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### Acceleration of a pulley system

The figure above shows a pulley system consisting of 3 masses ($m_1$, $m_2$ and $m_3$), a homogeneous wheel (radius R, mass M) and 2 massless pulleyes which are connected by a massless rope. Mass $m_1$...
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### Bidirectional jerk motion on a stopping vehicle

A stopping vehicle (say a car) has an apparent retardation (which may/may not be constant in magnitude) when force via brakes is applied. I travel by subway trains, and I noticed an odd phenomenon. ...
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### Are Newton's laws invalid in real life?

One of my friends and I had an argument over this topic. He stressed the fact that in real life many forces exist, whereas in physics we deal only with ideal situations. He put the following arguments:...
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### Calculating resultant force along vertical axis when using smartphone accelerometer [on hold]

I'm making an app which is using accelerometer to automatically detect damages on the route while driving. To estimate if damage occurred or not I'm using accelerometer (acceleration along vertical y ...
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### Max weight the lid of a vacuum can hold [on hold]

I have a box with a lid that has a mass object inside of it. I will be creating a vacuum inside of it with a $4~\mathrm{HP}$ Shop Vac that has a sealed pressure of $59~\mathrm{psi}$ and an airflow of ...
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### If the strong nuclear force is stronger than electrostatic repulsion, why don't nuclei collapse into a point?

Today in class we were discussing the strong nuclear force, and our teacher was explaining about how the strong nuclear force counteracts the repulsion force between protons in a nucleus. When asked ...
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### What causes more damage, a head-on car crash at 30km/h or one car at 60km/h crashing into a stationary one?

Which will cause a greater impact? Two identical cars colliding head on (in opposite directions), each going at $30\;\mathrm{km/h}$ OR One car travelling at $60\;\mathrm{km/h}$ colliding into a ...
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### a spring is stretched 10mm by a weight of 2.0N calculate the force constant k [on hold]

stretched 0.01metres weight of 2.0newtons calculate force constant k calculate the weight of an object that causes an extension of 80 millimetres
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### Newton's Second Law Confusion [on hold]

I don't quite understand the relationship between an object's mass, acceleration and net force. For example, if a car was going to the right at a constant velocity or with no acceleration, does that ...
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### Force and dimension is the same? [on hold]

I read somewhere that maybe we have 10 dimensions. We know that we have four dimensions (3 dimensions of space plus one of time). There are also four forces: gravity, electromagnetism, the strong ...
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### Force dependence on velocity : Drag

I just listened to the second lecture of Leonard Susskind on classical mechanics where he discussed that force can't be proportional to velocity, since it's unable to retro-dict (predict past). He ...
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### What really is force? [duplicate]

I know the second law of Newton says $F=ma$ which seems to me the most fundamental expression of the force. In other words, force cannot exist without a "forced" one. It is somehow a "secondary" being,...
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### PVC Pipe ideal force [closed]

A longbow is made with a string which is not stretchable and is made with a PVC pipe of radius of around 1 centimeter on the outer and 0.8cm on the inner radius. The pipe is 120 centimeters and the ...
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### Does displacement affect force? [closed]

I am sorry for being unclear with my previous question. The main topic of the experiment we conducted was about work. As we learned: $W = Fd$ Work, from my understanding, is the product of work and ...
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### Work done by internal forces of a rigid body

I am reading Goldstein's Classical Mechanics book, and I came across that: In a rigid body the internal forces do no work Is this statement based on the assumption that the internal forces are ...
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### Movement of a bobbin thread when pulling it's thread at certain angles [closed]

The problem: You try to move a bobbin thread by pulling it by it's thread. If you pull it while the thread is horizontal it slides your way but if it is at an angle the bobbin thread starts rolling ...
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### All about Frictions. (Help me) [closed]

A 20-kg body is on a plane inclined at 60° from the horizontal. The coefficient of friction is 0.22. What force at 30° with the plane will cause the body to move upward at a uniform speed? 2.A block ...
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### Pseudo/Fictitious force [closed]

A man is acclerating towards an object at rest. Accleration of the man is 2m/sec sq. , mass of the object is 2 Kg. What is the pseudo force on the object?
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### Validity of Point Mass Approximation in Newton's Laws of Motion

Chapter 2 of Kleppner & Kolenkow's An Introduction to Mechanics reads as follows - Newton's Laws describe the behavior of point masses. In the case where the size of the body is small ...
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### Why does the gluon meditation force between hardens become stronger with distance? [duplicate]

Also how factual is the explanation? Is it mostly philosophical like say Many World's 'theory' or is the explanation pretty straight forward with little to no dispute?
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### How did physicists conclude that 98% of mass is due to the strong force?

On a video on YouTube called 'weak and strong nuclear force (9/15)' at 0:55 a scientist said that 98% of mass is due to the strong force.
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### How does a position based force work on a torus?

Consider a 2 particle system in $\Bbb R^2$. Let's say they have some force acting between them. For the sake of argument let that be $F=\mathbf r/|\mathbf r|^3$. This is a simple inverse square system ...
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### Is it mathematically wrong to use units instead of words/parameters/names in equations?

In equations that have quantities with physical dimension. Example: $\mathrm{Force} = (\mathrm{mass})(\mathrm{acceleration})$ or $F=ma$ I know that we use that (mass, force...) to help what we ...
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### Conservative and nonconservative forces

I have learned that work done by conservative forces is independent of the path followed between initial and final position. But that's not the case for non conservative forces, they depend on the ...
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### Rotation of a rod due to a normal force

Suppose there's a rod suspended in space free from the effect of any force. Let a force F act at a distance x from one end. How can i prove that rotation will take place about an axis passing through ...
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### What is the resolution of this Lewis-Tolman like paradox?

Though my question stands on its own, here is a brief overview of a well-explored question which I think might be helpful in finding the resolution to my question. The Lewis-Tolman Lever Paradox has ...
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### How to determine my position using Coriolis effect?

The Coriolis effect is the effect that causes wind and water and moving objects to curve clockwise in the northen hemisphere and anticlockwise in the southern hemisphere, so how to determine my ...
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### Bigger tire/Smaller Tire

On a track, bigger tires have more contact therefore more traction. However, it comes at a cost of more unsprung weight. Therefore, the 0-60 time is slower as tested by Car And Driver. This was tested ...
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### How far would an arrow go in a space station and still be deadly?

So I was answering a question on the WorldBuilding SE site and one aspect of my answer made me wonder. Imagine you are on a massive space station of unlimited size. If you were to fire an arrow from ...
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### How to determine the overturning moment on a stand alone, uncovered bean pole tipi

I will preface this by saying I am a highschool student who has not yet had a physics class. I engineered and built a hexagonal shaped, open bottomed, planter to hold soil that would contain pole ...
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### Why does weight on Earth have a tangential component?

I read in Pulsar's answer of this question that weight has a tangential component due to the rotation of the (assumed spherical) Earth but I don't understand this. Can someone expand on it please?
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### Weight Detection Under Concrete/Asphalt [closed]

Consider that a weight sensor was embedded in a road. Would cars that drive over it trigger the sensor? I was thinking it'd look something like this (if we ignored the downward force that the ...
Two blocks each of mass $m$ are placed on a rough horizontal surface and connected by mass-less in-extensible string as shown.The coefficient of friction between each block and ground is $\mu$ What ...