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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0
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1answer
49 views

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 $m_1$...
6
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4answers
554 views

Are fields intuitive choices to explain forces?

Fields are used to explain all the forces with respective particle being their facilitators. However, are fields intuitive choice to explain the forces? The physical significance is not very apparent. ...
1
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1answer
20 views

Force of repulsion between northern and souther hemisphere of charged sphere

A metal sphere of radius $R$ carries a total charge $Q$. What is the force of repulsion between the northern hemisphere and southern hemisphere? In this problem you consider the force per unit area ...
13
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3answers
4k views

Slinky base does not immediately fall due to gravity

Why does the base of this slinky not fall immediately to gravity? My guess is tension in the springs is a force > mass*gravity but even then it is dumbfounding.
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0answers
18 views

Calculation of the angle between the forces when the other angle is given [on hold]

Two forces A and B acting at an angle D their resultant R will make an angle F with the force A.determine the value of $\cos F$.
0
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2answers
116 views

Work energy theorem explanation

So there is this problem in my head, it may seem very simple, but I need an answer. The problem is, we have some object, and we apply a force by our hands with a constant speed from a position (1) to ...
8
votes
9answers
4k views

Gravitation is not force?

Einstein said that gravity can be looked at as curvature in space- time and not as a force that is acting between bodies. (Actually what Einstein said was that gravity was curvature in space-time and ...
10
votes
9answers
6k views

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:...
5
votes
3answers
2k views

Torque direction meaning

I apologize if this question is dumb, but I've looked all over for a straightforward answer and either I can't find one or the terms are too complex for me to understand. I have only a rudimentary ...
2
votes
2answers
217 views

Balancing forces on a liquid [closed]

My reasoning is as follows Atmospheric pressure = $P_{0}$; Spring stretch = $x$; Pressure under top piston = $P$ Balancing forces on top piston $kx + P S_1 = P_0 S_1$ Balancing forces on bottom piston ...
6
votes
1answer
36 views

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. ...
-2
votes
0answers
33 views

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?
5
votes
4answers
115 views

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 ...
14
votes
2answers
1k views

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 ...
1
vote
1answer
417 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 ...
4
votes
2answers
2k views

Average Force vs Net Force

The $F$ in $$\mathrm{Impulse} = F\Delta t$$ is said to be the average force. For a ball dropped vertically onto a horizontal surface, the average force, F, on the ball from the floor is: $$F = \frac{\...
3
votes
2answers
142 views

What happens to forces when a charge travels at near c?

Suppose 3 electrons are travelling at $c - 1$mm at 1 cm distance The charges are at rest relative to one another in their frame, but what happens to fundamental forces Fe and Fg? What Fe does A get ...
3
votes
1answer
305 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 $$\frac{d^2u}{d\...
-2
votes
1answer
32 views

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 ...
1
vote
0answers
26 views

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 ...
1
vote
2answers
118 views

Sliding blocks problem

My first post here, so I apologize if this is duplicated elsewhere. It IS a "homework" problem, but it's public domain, a posted exam with answers... http://www.mun.ca/physics/undergraduates/...
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votes
0answers
16 views

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
1
vote
3answers
608 views

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 ...
-3
votes
0answers
39 views

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 ...
2
votes
1answer
138 views

How to calculate impulse force of body hitting water?

I'm calculating the force of a body hitting water from a high height. So far I've figured out the velocity at the time of collisions would be 40 m/s. The body is 78 kg. I seem to need the time it ...
0
votes
2answers
140 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 ...
-2
votes
1answer
30 views

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 ...
2
votes
4answers
288 views

Rate at which a pendulum bob slows due to air resistance?

I know that "perfect" pendulums would be able to swing forever, unperturbed by air resistance. However, since there is air resistance around us, pendulums (swinging bobs) slow down and move closer and ...
-1
votes
1answer
41 views

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 ...
0
votes
2answers
165 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
0answers
36 views

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,...
0
votes
1answer
120 views

Problem in constraint equations

In this, if I want the acceleration constraint between $M$ and $2M$, I write $AM+2AB$=LENGTH OF STRING, which on differentiating twice gives $a_{m}=2a_{2m}$(which turns out to be correct). However, if ...
5
votes
2answers
10k views

Understanding tension

I'm trying to understand tension. So here it goes: I'll start from the beginning. Let's assume I'm in space and can move around and apply forces. Let's say a rope is attached to a body(which is in ...
1
vote
2answers
48 views

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 ...
0
votes
0answers
15 views

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 ...
2
votes
4answers
291 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 ...
2
votes
1answer
125 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 ...
3
votes
2answers
129 views

How can photons cause charges to attract? [duplicate]

Photons are the force carrier of the electromagnetic force. I do not see how this could result in a transfer of momentum that attracts objects together.
1
vote
4answers
289 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
votes
0answers
12 views

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 ...
-4
votes
0answers
39 views

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 ...
0
votes
0answers
21 views

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?
0
votes
1answer
63 views

Wheel Sinkage Depth

I am trying to make a realistic car physics simulation for my game and the current thing that I am fighting to solve is rolling resistance. Although it's effect is minimal, this is important concept, ...
1
vote
1answer
85 views

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 ...
2
votes
2answers
185 views

Effect of position on a motorbike turning

While searching tips for driving a motorbike on wet roads safely, I heard some pilots saying to lean inside the slope makes the bike less tilted, so it's safer. I agree leaning make the bike less ...
2
votes
2answers
43 views

Why is $mg$ positive and $N$ negative in this problem?

In this problem: A car of mass $430\ \mathrm{kg}$ travels around a flat, circular race track of radius $178\ \mathrm{m}$. The coefficient of static friction between the wheels and the track is $0....
2
votes
2answers
63 views

Why would a moving infinite region of magnetic field exert an electric force?

I'm confused about the Lorentz force in relation to the frame of reference. There are many questions about that here, but I still don't get it. I've tried to break it down to the most basic example. ...
-1
votes
3answers
729 views

Where does the force to stop a constant velocity object come from?

If a ball hits a wall at a constant velocity, it will slow down and eventually come to rest. Since the ball was at constant velocity, it was not accelerating, and so there was no force. Also, the ...
0
votes
2answers
32 views

Pressure in deodorant can

Pressure in a deodorant can is greater than the surrounding pressure but still the can is in equilibrium with the surrounding . Why does this happen. If we apply $F = PA$ then $P_{in}A= P_{atm}A$ and ...
0
votes
4answers
296 views

Work and free body diagrams

I am a bit confused with how to find work when there is a free body diagram. I am trying to work out this problem, and in it a box is being pulled at a constant speed by a rope at a constant angle ...