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 ...

learn more… | top users | synonyms (1)

4
votes
0answers
163 views

Calculating Forces via Feynman diagrams?

How would one go about calculating forces that test objects feel using Feynman diagram methods? For example, say we have a massive object in GR so that the metric takes on the standard ...
3
votes
0answers
3k views

Forces and torques about the CENTER OF MASS of a physical pendulum

I'm currently stumped by the following situation. Say we've got a rectangular physical pendulum (think ruler with a hole-punch at one end). It's trivial to analyze the motion of the pendulum with the ...
2
votes
0answers
66 views

Deriving the formula for energy stored in a spring without using geometry (determining the area under a curve)?

Using Hooke's Law, we know that the force applied is proportional to the extension of the spring. Therefore by plotting a graph of force against extension, through the area under the curve we are able ...
2
votes
0answers
27 views

Could a hydrophobic surface increase a liquid's resistance to compression/displacement?

Imagine a quantity of an aqueous (yet slightly viscous) solution is resting on a hydrophobic surface with a contact angle around 100°. A downward force is then applied as a (repellant) surface is ...
2
votes
0answers
132 views

Lagrange: when a potential force, when a generalized force?

Consider the following case of a drum unrolling a mass that is on a massless string wrapped around the drum: According to my professor, here we must consider the mass $m$ being in a gravitational ...
2
votes
0answers
183 views

Lorentz force on superconductor vortices

I am reading a paper on superconductivity and in it it says that the vortices are subject to a Lorentz force given by $$\vec{F}_L=\frac{\Phi_0\vec{I} \times \vec{H}}{cH}$$ Here $\vec{F}_L$ is the ...
2
votes
0answers
35 views

What kind of forces would follow only the second part of shell theorem?

General expression of a force which would cancel out inside a uniform hollow shell. What about any closed surface?
2
votes
0answers
103 views

Force and Energy in robots

There are two similar and hypothetical robots that move with wheels powered by motors, Robot A and Robot B. Robot A has a gear ratio of 3:1 (The gear connected to the motor is three times larger than ...
2
votes
0answers
217 views

Odd experiment results (electromagnetics)

Okay, a bit of background. So I'm working on a linear accelerator (you might know it as a Gauss rifle), and I had worked through the equations I thought I needed (Magnetic force, displacement, etc.) ...
2
votes
0answers
189 views

Magnetic Force on a Ferromagenetic Material

I am currently working on a project involving solenoids, and I needed a force(Newtons, not a measure of magnetic field strength) equation. What I came up with after some digging around on the ...
2
votes
0answers
69 views

How is force felt at relativistic speeds?

Hypothetically, should a force feel the same as its measured force at relativistic speeds? Obviously a human body would not survive the force of a rotation at say, 0.6 the speed of light, but it’s ...
2
votes
0answers
604 views

Sum of energy in a free rotation with Algodoo software

I try to understand why Algodoo software (freeware) give an efficiency greater than unity. I tested several scenes and at each time I can look the software give energy, I don't say it's all the time ...
2
votes
0answers
176 views

Balloon tethering cable tension model (catenary tether)

If a moving balloon (let's say it's a blimp system with some rotors for movement) is connected to the ground by a cable that describes a catenary curve, how can we model the tension being applied on ...
2
votes
0answers
105 views

what forces are present when slicing an object.

I found here:What happens when we cut objects? that it is due to fracture wood splits open when using a wedge. Does it only apply when the wedge is already in the wood? How about the moment before a ...
2
votes
0answers
63 views

Time evolution of symmetrical mechanical systems

I asked this previously in an earlier question, although admittedly my question was hard to find in the slew of info I provided there, so hopefully this will clarify things. Suppose there's a typical ...
2
votes
0answers
173 views

How do we derive force/acceleration vectors from Einstein's field equations?

I'm new here and I don't have any formal experience in physics beyond A-level. I've been exploring an idea for a space sim game someone else is developing in which propulsion of a spacecraft is ...
2
votes
0answers
259 views

Modeling Syringes e.g. with the ideal gas law

Gentlemen I have a similar yet very practical problem that might provide further insight. I'm trying to model a moving plunger in a syringe (something like a piston in a cylinder). At time zero the ...
2
votes
0answers
95 views

Consistency of equation with special relativity?

The following is the equation which, I want to know, if it is valid in relativistic domain. Consider two equal charges moving in same direction with velocity $v$ and charge $q$ at a separation of ...
2
votes
0answers
365 views

What is wrong with this downforce calculcation?

I tried calculating the downforce of a spoiler I need for a robot. I used this formula. $$F = \frac{1}{2}Ac_a\rho v^2$$ Where $\rho$ is air density, $v$ is the speed of my robot, $c_a$ is the lift ...
2
votes
0answers
162 views

Robot controling pouring process from a bottle

I need to solve a problem within mechanic of fluids for a part of my thesis. Robot will pick up a bottle of beer, cola, julebrus or any other kind of beverage. And then it has to bring it to the glass ...
2
votes
0answers
202 views

Semiflexible discrete polymer chain

Suppose we have a 2D polymer model described by a set of 2D vectors {$\mathbf{t}_i$} ($i=1,2,\dots N$) of length $a$. The energy of the polymer is given by: $$ ...
1
vote
0answers
47 views

Does a ball bearing cause bigger tides than the moon?

As per the answer to this question it is suggested the relative tidal pull of objects of equal angular area is equal to their relative density. Which lead me to the click-baity question: Does a ball ...
1
vote
0answers
20 views

What is a simple model to find the jump height for the Thomson's Jumping Ring experiment?

I'm trying to devise a basic formula that could give a rough estimate for the jump height reached in the Thomson's Jumping Ring experiment, as detailed here. However, it's pretty difficult as most ...
1
vote
0answers
20 views

Kinetic energy vs Kinetic Energy scenario in a collision, mechanical energy used for work?

Most collisions have Kinetic energy conserved or in the case of inelastic collisions energy is lost into other forms. Though the equation of "TMEi + Wnc =TMEf" is true however, what if two unequal ...
1
vote
0answers
19 views

How to measure the properties of a non-newtonian fluid?

We have made non-newtonian fluid by mixing water (or Tonic) and starch. We can't figure out the link between the amount of water and starch and the viscosity of the fluid. What we can figure out is ...
1
vote
0answers
30 views

Superstring mass between 2 D-branes

The mass of a superstring between 2 parallel D-branes of dimension $p$ and $q$ is $$m^2=(N−a)+(y/2π)^2$$ But what is the value of the normal ordering constant $a$?
1
vote
0answers
57 views

Why are symmetrical structures highly stable?

What makes symmetrical structures(geometry) highly stable? It is perfect to say that the forces acting on a symmetrical structure is balanced and hence stable. But why is it so? To be more specific, ...
1
vote
0answers
89 views

On the nature of forces in general relativity

*** EDIT: I understand that it's not wise to fixate on Schroedinger words, however their meaning still remains obscure to me. Besides this my question on the possibility to abandon the concept of ...
1
vote
0answers
50 views

Free body diagram of pulley

Is there any difference between the free body diagram of fixed pulley and movable pulley? I've read that both of the rope of fixed pulley and movable pulley have the same direction (both upwards or ...
1
vote
0answers
103 views

Why do trees sway?

Resonance can also occur in three dimensions (such as wind induced swaying) I tried to make a free body diagram (I know it is terribly wrong) to find the forces that causes the tree to undergo ...
1
vote
0answers
53 views

Calculus formulas for buoyant force?

I am launching a high-altitude balloon as a part of a physics project I am working on. I know that the amount of helium I need corresponds to about 40 newtons of lift for the launch, which is all I ...
1
vote
0answers
88 views

Centripetal force at the pole is different from the equator

why is the centripetal acceleration in the poles and equator if different? I know that it's related to Equatorial budge. But what I don't get it is that the centripetal force is zero at the poles. ...
1
vote
0answers
12 views

Field line Direction and exerted force

Magnetic field lines of a magnetic field have different directions. What information about the force exerted on a charge will give us the direction of field lines?
1
vote
0answers
28 views

Relationship between magnetic force acted upon a diamagnetic substance and the magnetic field applied to it

I have a sample of bismuth that I have applied a measured B-field to through the use of a solenoid electromagnet. I've been trying to find a formula relating the B-field to the force that the bismuth ...
1
vote
0answers
36 views

work done in observer frame

I had a few questions. 1) Is work done independent of the refrance frame? 2) Suppose a cart-A with rough surface is accelerating with an acceleration a and another cart-B with acceleration b. Now to ...
1
vote
0answers
76 views

Uranus, the Physical model to change it's rotation axle

Uranus rotates pretty wierd, it's 90-degrees tilted; Why is Uranus's axis of rotation tilted? The best answer for this is; that at a distant point in its past, Uranus was struck by a very ...
1
vote
0answers
73 views

Potential Energy of two masses

If two particles with masses $m_1$ and $m_2$ interact and are located at $\vec{s_1}$ and $\vec{s_2}$ have their potential energy $U$ defined by the modulus of their position vectors, how would I ...
1
vote
0answers
57 views

Friction of an object falling between two walls

I'm simplifying this problem into 2D for easier understanding. Lets say we have 2 vertical walls separated by distance x. Inside these walls I place an object that is only slightly smaller than x in ...
1
vote
0answers
36 views

irreversibility Aristoteles law of motion

I am watching the second lecture from the theoretical minimum and do not understand the argumentation of Susskind. For those who do not want to watch the video. It is about the law of motion from ...
1
vote
0answers
52 views

Magnetic levitation project

For the past four years, I have been working on a project that will allow permanent magnets to levitate stably above a magnetic surface. So far I have tested my first theory which was to see if ...
1
vote
0answers
58 views

Reaction forces

If a cyclic lamina (in equilibrium) is supported from two points that are of equal distance from the line joining the centre and the lowest point of the circle (so the arrangement is symmetrical ...
1
vote
0answers
91 views

Impact Force/Pressure of a wave on a vertical wall given PIV velocity field

I have PIV (Particle Image Velocimetry) data of liquid sloshing on a rectangular tank which produces a wave impacting one of the vertical walls. In the picture below you can see the wave about to hit ...
1
vote
0answers
66 views

Find the force and the torque so that the cylinder is in balance

At the cylinder of the picture there are static pressures from environment fluid of density $\rho$. If we neglect the atmospheric pressure, calculate how much force and how much torque is needed so ...
1
vote
0answers
35 views

Solenoid expressions

I am wanting an expression for the nearly uniform force (not magnetic force) through the central axis of a solenoid, with a nonmagnetic tube but coiled wires with fixed current, and an explanation of ...
1
vote
0answers
135 views

Motion in a vertical circle and forces in polar coordinates

Suppose a particle with mass $m$ is whirled at instantaneous speed $v$ on the end of a string of length $R$ in a vertical circle. Let $\theta$ be the angle the string makes with the horizontal. I know ...
1
vote
0answers
94 views

Mass flow rate and force on moving disk

If I understood correctly, the force $F$ related to a given mass flow rate $\dot{m}$ through orifice area $A$ (or, say, on a disk of area $A$) is given by Newton's 2nd law of motion - assuming a ...
1
vote
0answers
59 views

Is there a typology of different fundamental physical objects?

As I understand it (and of course, I may be wrong!).... In classical mechanics, all objects are basically the same in the sense that They are composed of atoms bunched together. These atoms occupy ...
1
vote
0answers
87 views

Discernible “frequencies” of magnetic fields that do not affect each other

Two magnets secured to a surface close to each other in a fashion such that their constant attraction to one another is counteracted by the normal force of the securement of each. Is there a way to ...
1
vote
0answers
642 views

Calculating the torque required to move a heavy object (the calculations)

I wanna choose a motor for my bicycle and turn it into an electric one. So the physics part shoots. The force (Force=Mass x acceleration) that i will exert on earth surface(weight) will be my ...
1
vote
0answers
101 views

Determining the attraction of a magnetic bob

I have a question concerning the calculation of the attraction to a ferromagnetic material in a coupled B-field, which of $N \geq3$ equally strong cylindrical permanent magnet is produced. ...