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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1answer
133 views

Can two bodies move with equal acceleration if forces acting on both are unequal?

In my textbook there is a case given that is to find acceleration and tension produced in a string passed over a frictionless pulley and attached with bodies of different masses at its ends. Now below ...
0
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1answer
34 views

Double Integrals of Force

I took AP Physics C and Multivariable Calculus last year, and noticed something interesting. For non-relativistic particles in one dimension:$$F=\frac{\partial p}{\partial t}=\frac{\partial ...
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1answer
22 views

Calculate the average force exerted by the bat on the ball [on hold]

A cricket ball of mass 150 g is moving with a velocity of 12 m/s and is hit by a bat so that the ball is turned back by a velocity of 20 m/s. The force of blow acts for 0.01 second on the ball. ...
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1answer
39 views

What kind of damping is this $F = -ax|x'|$?

From Applied Mathematics by Logan: A mass hanging on a spring is <...> governed by $$mx'' = -ax|x'| - kx$$ where $-ax|x'|$ is a nonlinear damping force. I looked up "nonlinear damping" ...
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0answers
42 views

Cavendish Experiment [on hold]

Would the earth’s gravity overpower the gravity of the much smaller and less dense lead spheres? which if this is the case, should equate to no movement?
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1answer
58 views

Height formula of a sphere inside a pipe

I have a pipe with a ball inside it and a blowing air through it. Look this image: The air is blowing in the direction of $F_a$. $F_a$ Is the air force and $P$ is the weight force. What I want ...
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0answers
24 views

Calculate force required to lift an object to a certain height in a required time [on hold]

This is my first question in stack physics so not sure if I'm phrasing this right. I'm a 9th grade student and this is not a school project. My idea actually. Anyways Say I have a object of weight ...
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2answers
36 views

Balancing Orthogonal Forces on 2D plane with arbitrary placement [on hold]

I have a rectangular block in the xy plane with the center of mass that acts in the z direction at an arbitrary place in the plane. I also have 4 legs that support this weight underneath the block. ...
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2answers
246 views

We cannot solve this inclined plane problem, right? [on hold]

We drag a sledge along a snow-covered hillside with constant speed. Distance is 150m. The time it takes to reach the top is 300 secs. The sledge is 12kg. And the coefficient of friction $\mu$ = 0.04. ...
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1answer
40 views

Why does a bungee jumper continue to move downwards beyond the equilibrium position of the jumper and cord?

When a bungee jumper jumps, ignoring the mass of the bungee cord, the jumper initially falls in freefall before an inelastic collision occurs between the jumper and cord, and the cord extends as the ...
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1answer
26 views

Energy Transferred to a Spring by a Time Dependent Force (using Fourier Transformations)

I found an excersice in Byron-Fuller's: "Mathematics of Classical and Quantum Physics", about the energy which is transferred to a spring by a time depended force of the form: $F(t)=\left\{ ...
3
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1answer
40 views

Force and Torque

Think of a uniform sphere. Sometimes if a force is applied to the sphere it does not only move but also spins. So there is a torque. But is it possible to calculate which part of the applied force is ...
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1answer
55 views

Raising a cut on your arm above your heart

I often read that when you have a deep cut on your arm, you should raise your arm to the point where the cut is above your heart. This should reduce the amount of blood loss because less blood reaches ...
1
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2answers
13 views

Difference in Energy Transfer Between Impacts and Nudges

Say I have a table and I want to produce a vibration in the table. Would I be better off impacting the surface of the table (i.e. smacking the table) or nudging the surface (i.e. leaning on the ...
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0answers
45 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 ...
3
votes
1answer
147 views

induction of van der Waals forces

Is there a way to maximize van der Waals forces between two materials, by electrifying one material, thus creating dipoles/instantaneous dipoles and thus creating stronger van der Waals forces? has ...
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0answers
26 views

How one fly using allomancy? [on hold]

Actually this question is related to the allomancy of Mistborn series. Suppose if there is body that can steel push. Then initial weight is balanced by normal reaction. froce due to steel push is ...
1
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2answers
370 views

Ball flying towards me - Newton's third law is violated?

I was trying to answer the question of the flying ball here on the basis of Newton's third law and momentum conservation. Here is what I have tried. Lets take a ball mass of $m_1$ (index 1 is the ...
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0answers
25 views

Could this garage door's bowing be caused by someone falling into it? [on hold]

The tension spring broke on our garage door causing it to fall. Afterward, the garage looked as it does in the pictures below. The most straightforward explanation to me is that the impact of the fall ...
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4answers
261 views

Forces Create Angular Acceleration And “Straight” Acceleration - But How Much Of Each?

Let me set up the following problem for a rectangle floating in space: We know its dimensions. We know its mass. There's a force pushing it for a known amount of time - we know the angle & ...
0
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0answers
19 views

Vertical Scale Acceleration Values [on hold]

The following is an acceleration-versus-force graph for a 500 g object. What acceleration values go in the blanks (a and b) on the vertical scale? I just need a little bit of coaching as to whether ...
0
votes
1answer
118 views

Magnetic interaction of wire and rectangular loop

In this video, Prof. Lewin shows an infinitely long wire and a rectangular loop at a distance $r_1$ from each other, each carrying a current. He then calculates the magnetic field resulting from the ...
0
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0answers
65 views

In the figure shown, what is the magnitude of the acceleration of the vertically suspended block as it falls? [on hold]

I started by drawing out the free body diagrams of both M and 2M and got: for block M i got the equation (looking at the diagram): $F_{down}=ma_{down}$ $T-Mgsinθ=Ma$ (D'Alambert's principle) ...
4
votes
5answers
592 views

What is the significance of Planck force?

I have been curious to find what could be the significance of Planck force? It is calculated by the formula $c^4/G = 1.21031359\times 10^{44} \, \mathrm{N}$, where $c$ is the speed of light and $G$ is ...
6
votes
1answer
437 views

Derivation of force law in special relativity

I've seen force defined in special relativity as the rate of change of 4-momentum $$ {\bf{F}} = \frac{d {\bf{p}}}{dt} $$ Can anyone comment on the following derivation of that relation? Take one ...
7
votes
5answers
133 views

Astronauts on a tether

Recently, I went to a competition with a science test. One of the questions was as follows: Two astronauts (A and B) are tethered together in space. Simultaneously, Astronaut A pulls on the tether ...
3
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0answers
46 views

Why is diproton unstable? [duplicate]

Diproton is an isotope of helium without any neutrons. It commonly forms in the Sun, where protons are fused constantly. However, it is extremely unstable, and will revert back to two protons almost ...
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0answers
24 views

What is the horizontal acceleration of the block? [on hold]

A 2.0-kg block slides on a horizontal surface. A force (P = 6.0 N) is coming at the block as a 30° angle pushing on the block to the right. What is the horizontal acceleration of the block? So ...
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votes
2answers
113 views

Few questions related to Tension

I am struggling with the concept of tension in a rope. Below specific questions. I am understanding tension to be an elastic force between rope molecules. If so, is it fair to say the net tension ...
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1answer
280 views

Question on Binet's equation

Is there a difference in Binet's equation when the force acting on a body is attractive and repulsive? I mean, if the force has a magnitude $F(r)$, is it Binet's equation always ...
4
votes
3answers
1k views

Has a body angular momentum and torque only in a circular path?

In different contexts, my book(Principles of Physics by Resnick, Halliday ,Walker) , they wrote For torque, the path need no longer be a circle and we must write the torque as a vector ...
2
votes
1answer
38 views

What amount of force could be created by a person “swimming” in air?

Had a question on a physics test, a person is at rest on a frictionless surface and can not throw anything, can they move? I said yes, by "swimming" against the air and got docked because "it ...
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3answers
38 views

How is rotational torque calculated when a force is applied uniformly over a surface?

Currently, the formula I am using to calculate the rotational torque applied onto an axis is $T = Fr\sin \theta$, where $T$ is the torque (in $\mathrm{N\ m}$), $F$ is the force acting, $r$ is the ...
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votes
0answers
20 views

solving force vector calculation [closed]

$AC= 1\ \mathrm{cm}\land3.8\ \mathrm{N}$ $AB= 17.5\ \mathrm{cm}$ Corner $ABD= \alpha$ Question: How many newtons is force vector $AB$? My solution so far is not even near the solution on the ...
1
vote
3answers
255 views

Centripetal and centrifugal force

If a stone is rotated with the help of a rope, then both centripetal force and centrifugal force will be liberated. The magnitude of that forces are same, but direction of them are opposite to each ...
0
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1answer
25 views

How does string tension influence the harmonic spectrum?

Hey there fellow physicists & musicians! I have a question both physics and music related. How does the string tension affect the sound spectrum? More precisely, how do the respective ...
1
vote
6answers
89 views

Elevator normal force

In the above case, the normal force exerted by the elevator on the box would be $= 10\mathrm{kg}\ g + 10\mathrm{kg}\ 5\ \mathrm{m/s^2}$, assuming $g = 10\ \mathrm{m/s^2}$, the elevator would exert a ...
1
vote
1answer
56 views

Is it contradictory with any theory or experimental result to have a negative gravitational force mass?

I am aware that there are many similar questions here about this in this site, but most answers concentrate on negative inertial and gravitational energy. My question is more specific. QM together ...
1
vote
3answers
65 views

What is the relation between Force, Physical Strength,Enery and Work?

I am sorry ,but, I am not much of science or a physics guy, if this question sounds stupid. Anyways, what is the relation between all of them. Like for example, does applying more force means more ...
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votes
1answer
31 views

FRICTIONAL force vs NORMAL force [closed]

Well As per the diagram the angle between frictional force (F) and the Total force(T) is 'A' . So F = TcosA and Normal Force (N) = TsinA And then F = uN where u = coefficient of friction of ...
1
vote
2answers
53 views

Model/formula for bouncing ball

I'm programming an animation of a bouncing ball, and I want it to be as realistic as possible. I fully understand the physics while the ball is rising and falling: It accelerates downward at 9.8 ...
0
votes
2answers
148 views

Force on border exerted by a liquid

Why is it nearly universally understood that force in a liquid against a border is dependent on internal pressure, depth only, rather than weight of the liquid? Thus, for example, that the force from ...
1
vote
2answers
67 views

Shelf always tipping over when pushed, thanks to normal force

A while ago, I encountered a problem with a person pushing a shelf at the top, with the center of mass located in the middle. The task is to find the maximum magnitude of the force vector, not causing ...
4
votes
1answer
66 views

What is the specific source(s) of sliding kinetic friction

In simplistic (K-8) physics classes, it seems to be generally instructed that the friction between two moving surfaces is due to the unevenness of each surface and the microscopic roughness. However, ...
1
vote
1answer
137 views

Work done by friction on a body?

I know that when a body slides over a surface, the work done by friction is not stored as potential energy in the body. It is dissipated in the form of heat. But why is it not stored as potential ...
0
votes
2answers
88 views

Finding Reaction forces in a truss [closed]

One of my tutorial questions is to find all the forces in the given truss. I know how to do all of it except that I cant find the initial reaction forces. Because the two reactions have both an $x$ ...
-1
votes
1answer
31 views

Non-uniform Normal force, friction

I got problems understanding the Non-uniform normal force. Why is it non-uniform? Because the object would have different densities in different parts, so weight would be greater in some parts? So ...
6
votes
1answer
208 views

How do I describe and calculate the effect of an impacting object?

My lab studies the physiology of impact injury on biological tissues. I use a pneumatic cylinder to impart injury into a biological sample and then assess the molecular and physiological changes in ...
1
vote
1answer
388 views

Force of a solenoid on a ferromagnetic material

As I was trying to find an answer to another problem, I was informed that the equation I was using would not work. The equation I was using was $$F = (NI)^2\mu_0\frac{\text{Area}}{2g^2}$$ If this ...
0
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0answers
16 views

Modelling point force with uncertain point of concentration [closed]

I consider a beam which is bent under influence of a point force concentrated at some point $\xi$ of the beam. The exact co-ordinate of $\xi$ is not known, but it is known a neighbourhood ...