# 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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### Question about Torque Reaction of a Helicopter

This image below about the torque reaction of a helicopter has confused me a bit. I would like to ask whether i understand the principles here correctly. In the picture we see a helicopter whose main ...
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### Estimate for energy dissipated by a damper/dashpot

I have a system with a mass $m$ attached to the end of a cable. The cable mass is assumed negligible. The cable is attached to the ground at the one end while the other, with the attached mass $m$, ...
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### rotation behavior of spinning discs

If two discs of equal mass and volume are parallel to each other but not touching, share an axle but using magnetics do not touch it, are not under gravity, and begin to rotate in opposite directions ...
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### What is meant by saying the work done by a conservative force is -(change in PE)?

I read through all related questions, and they are almost the same, but I still didn't understand this and so am asking again. What is meant when we say that the work done by conservative force is = -...
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### Third law of motion when action and reaction are separated by some time

For every action there is an equal and opposite reaction. I have used this law only when bodies are in contact with each other which means for every action reaction is produced at same instant of time....
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### Does a rotating object have more inertia, mass and gravitational pull?

When an object is rotating on an axis, it has stored rotational energy in it. Since energy and mass are related, does this stored rotation increase the mass of the object? And if so, will it be harder ...
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### How force is transferred from one body to another

If there are 3 coins , namely 1 , 2 and 3 as in figure. When coin $1$ strike coin $2$ ,the coin $2$ passes the force to coin $3$ and the coin $3$ moves away. Case :1 How does this happen? What ...
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### Force on side of pool from water

Given a pool with dimensions $$\ell \times w \times h \, ,$$ I am trying to derive an equation that will yield the force by the water on the sides of the pool, namely \ell\times h \quad \mathrm{or} \...
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### Why is force called the rate of change of momentum? [closed]

Why is force called the rate of change of momentum? If I push a wall I do exert a force but there is no movement; so is there force acting on the wall?
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### Circular Banked Track Normal [closed]

I don't understand the phrase 'the total pressure exerted by the car on the track is normal to the plane of the track.' Is the pressure the weight of the car, so does the normal = mg? I have tried ...
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### How charges can be at rest if there is a force on it?

Electrostatics deals with forces between charges at rest. But if there is a force on a charge, how can it be at rest? My guess is that charges is being kept at rest by some unspecified forces that ...
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I noticed that the bulk modulus often has a negative sign appended to it in order to cancel with a negative change in an object's volume; this allows the bulk modulus to be positive. However, I ...
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### Instantaneous cause [closed]

The position of an object has a rate of change called velocity. The velocity of an object has a rate of change called acceleration. Force applied is proportional to the acceleration of the body (...
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### Derivation Electric force

I’m a physics of high school (SMAN 3 Bandar Lampung, Lampung, Indonesia 35116). I make the experimental apparatus in static electric field. Instrument arrangement in the image below: The theoretical ...
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### What are the most efficient ways to transmit force through air? [closed]

I am taking part in a robotics competition, where the challenge is to create a pair of robots which successfully navigate a series of obstacles. However, the rules state that of the two robots, only ...
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### 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 ...
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### Repulsive Force between two Electromagnets

This question might seem a bit too basic(or advanced!), but it is the one to which I'm really desperate to find a simple enough explanation and solution. Ok, So here's the problem, I have two ...
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### Physics pulley problem [closed]

A 64-kg housepainter stands on a 14-kg aluminum platform. The platform is attached to a rope that passes through an overhead pulley, which allows the painter to raise herself and the platform. (Ignore ...
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### Pushing an object in orbit outwards

I wonder what would happen if an object in orbit were to be pushed outwards. I can imagine 2 outcomes: either it would keep spinning outwards away from whatever it is orbiting at a finite speed ...
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### Does Light have Weight?

If I light a torch and hold it against a wall, will the wall feel any force? If yes, what factors does the magnitude of such a force depend upon? (Area of the wall covered by the beam, intensity of ...
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### Which travels further, a football or a soccer ball, when thrown?

I recently answered this question: Laminar Versus Turbulent Flow and it caused me to think of the following situation. Given that an (American) football weighs between Football 400 to 430 grams, and ...
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### are 2 parallel magnets stronger than 1?

if I have 2 parallel magnets of neodymiun the force of them woul affect in the same as just one or increase? I have heard that the force would be the same and the only difference in that case is that ...
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### Can a pilot in a small spaceship feel G force in space?

I am not really good in physics so I might be wrong at some points, but here is the situation. Consider a spaceship of the size of a fighter plane. And like a fighter plane, the ship is very mobile. ...
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### Does every force which seems to have no effect cause a deformation?

The example in our discussion was: If I glue a peanut to the ceiling, does the ceiling bend? Some people argued that it wouldn't because ceilings do not bend for peanuts. Some people argued that the ...
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### Why does ice fall from the top of the ice tray first?

I haven't found an answer for this anywhere, so hopefully this community can help. It's not important at all that I know this but I'm curious. If you take a plastic tray of ice from the freezer and ...
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### How is the fall time for a parachute affected by the mass of the load?

Why do parachutes with a heavier load fall faster than a parachute with a lighter load?
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### Reaction force explanation? [closed]

I heard that reaction force is the total force applied back due to electromagnetic repulsion between the atoms of the thing that exerted the force and the thing that the force was exerted on, so can ...
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### Gravitational force acting on two particles

According to Newton's Laws of Gravitation, $F=Gm_1 m_2/r^2$ So gravitational force F is directly proportional to $1/r^2$. Now if we consider 2 point masses in vacuum at rest at a distance 'd' apart,...
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### Does Hooke's Law apply for microscopic amounts of compression?

I would like to set up a simple laser interferometer to measure the compression of a material experiencing forces around $8 \times 10^{-4}$ N. But I need to find the spring constant to calculate the ...
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### Is work done by a pseudo force?

If a body is viewed from the frame of another body which is itself accelerating, will work be done by the pseudo force acting on the first body in the frame of second body ( provided the first body is ...
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### Formula connecting Force and Power

Is there such formula? There probably is of course, but i would like a very concise description of how to derive it, in order to better understand myself. Thank you in advance.
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### Diamagnetic Sphere Moving through Solenoid

I've seen the videos of frogs being levitated due to diamagnetism. What happens if the frog (or another diamagnetic object) enters a solenoid with an initial velocity? Specifically, consider a ...
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### Does the frame of reference change the behavior of a particle

"Behavior" word in the title is not very correct. I'm in a train at a railway station and on the platform there is a glass case (the mass of case is 5 kg and if it gets hit with a velocity of 10 N ...
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### Calculating output forces of bicycle wheels

Based on the force on the rear gear $F_t$ and the radii of the rear gear $R_g$ and rear wheel $R_w$ , how would you calculate the force the bicycle exerts on the ground when it is accelerating? I ...
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### Calculate Spring Constant [closed]

I am editing the question because it was misunderstood to be a homeowrk question. I am modeling a Stumps equipment for a game called Cricket.Typically the game consists of 3 wooden stumps ...
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### Why does the superposition principle work in method of images?

Okay, let there be a conducting sphere having radius $a$ initially charged with $Q$ & insulated. Now, $q$ is brought in front of the conductor at $y$ from the center. Now, Jackson in his book ...
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### Horizontal and vertical acceleration of a ball on a slope?

I understand that you resolve the components of the balls weight parallel and perpendicular to the slope in order to calculate the force due to gravity that actually acts down the slope. The ...
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### Pertaining to Newton's laws, how do so many objects acheive perfect equilibrium?

Suppose a light is hanging from a ceiling. Supposedly, the force of tension pulling it up is exactly the same as the force of gravity pulling it down. Why is it that the tension happens to be exactly ...
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