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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2answers
90 views

Gravitational force in a building

Suppose that a person is standing on the top of a multi storey building and at an instant earth's gravitational pull becomes zero.What will happen in the next instant? (Consider only earth's gravity ...
1
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1answer
26 views

Half of a uniform disc suspended by two strings [closed]

Suppose we have a half of a thin, homogenous disc hanging from the ceiling as shown: Given the weight of the disc $Q$, calculate tensions in strings $S_1$,$S_2$. Now this seemed like quite a simple ...
2
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0answers
64 views

Force required to crop/cut a mild steel bar [closed]

I have cropping wedges with a diameter of 4mm cutting either side of a round mild steel bar (17.5mm). These wedges are operated using 2 hydraulic cylinders (6" diameter, 2 1/2 travel) (one for each ...
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1answer
59 views

Coefficient of elasticity of the spring?

I know this might sound a silly question though For a spring that is compressed lets say x meters by a force F N. what is coefficient of elasticity of the spring? We are not given the equilibrium ...
2
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3answers
227 views

Weight distributions [duplicate]

If a man is standing on two weighing machines (scales), with one foot on each, Will both machines show equal weight or his weight will be distributed in two machines?
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0answers
20 views

How is the strength of a force quantitatively evaluated?

Physicists often talk about the 'strength' of a force. For example, gravity is weak, the strong force is of course strong. The hierarchy is summarized on this wikipedia page, which lists strengths in ...
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1answer
331 views

Maximum range of projectile launched from an inclined plane [closed]

As we already know the max range if we launch it from any flat surface or from any height but I was wondering what will be maximum range if we launch it from inclined plane. I have made on figure of ...
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2answers
127 views

Why do we feel resistance to gravity rather than the acceleration of gravity?

What's the reason it behaves differently from all other forces? What I mean is, if you're in orbit you're accelerating toward the earth at almost 9.8m/s^2, but you feel nothing. If you are riding a ...
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votes
1answer
73 views

Force in a moving object that is not accelerating

If an object is traveling in a straight direction at a constant speed it has no acceleration, right? So if $F=ma$ and $a =0$ then force should equal 0. Does that mean a car traveling at a constant ...
2
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2answers
80 views

Does friction act on a wheel rolling at a constant speed

One of the things I've seemed to have taken for granted is that its the friction the floor exerts on a rolling wheel that prevents slip from occurring. However, I ran into something that challenges ...
0
votes
1answer
38 views

What does “interact via strong force” mean?

I was just wondering if the words "strong force" and "strong interaction" are interchangeable? Also, these are referring to "strong nuclear force", correct? Then what does it mean for particles to ...
0
votes
1answer
62 views

Force Needed To Maintain Velocity, Increasing Mass

Hoping somebody could give me a hand with this. Unfortunately I haven't taken physics yet, my background is in math/computer science. I'm studying computational science and the problem is essentially ...
2
votes
4answers
439 views

What causes a car's velocity to follow the front wheels' direction?

I'm trying to simulate a car with correct physics models. In this example we let the car have a constant speed, and there are no forces (friction and drag) to slow down the speed. Here's a video that ...
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0answers
18 views

The contact pressure on a solid surface by a rod connected to a solid piston?

Below I have two pictures, one of which is single piston (blue) made of a solid material inside of a chamber (black) and the rod (magenta) is in contact with a rigid surface (teal). The second picture ...
2
votes
2answers
35 views

Formula for balance with three arms?

I'm searching for a way to express the angle of the arm of a balance instrument expressed in the weight that is present in one arm. For a two legged balance one could use the moment formula: moment = ...
0
votes
1answer
33 views

Buoyant force on a certain object

Sometimes a certain body is completely immersed in water, but it does not sink deeply, it is stuck in the middle... In this case, is the buoyant force equal to the weight of the body? Why?
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1answer
38 views

Is force exerted by Earth different for different mass?

We know Earth pulls every object by the same acceleration $g$ (say). force exerted by earth $F=m\cdot g$ (with $m$ the mass of the body), so, if $g$ is constant then $F$ is directly proportional to ...
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1answer
42 views

Definition of Force Using Momentum

When we use F = change in momentum / change in time, is that the average force applied? There could be different magnitudes of force applied over time to change the momentum (it could be instantaneous ...
0
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1answer
42 views

Pressure and force of ideal gas in a leaking container?

Let's imagine you have a container that has a pressure of 10 Pascals inside and a vacuum outside. The container has a volume of a cubic meter and I'm not sure if the temperature matters but lets say ...
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0answers
52 views

Is the acceleration of a soap bubble the standard value of gravitational acceleration?

Is the acceleration of a basic soap bubble the same as the standard value of gravitational acceleration 9.81 m/s^2 when it is dropping in a windless space? I have used the Newton's 2nd law to prove ...
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0answers
36 views

Forces acting when we squeeze a ball?

I have few doubts to clear. I would like to know the forces acting when we squeeze a foam ball. Mode of squeeze will be by placing the ball between the palm of the hand and the four fingers. What ...
3
votes
3answers
122 views

Force Body Diagrams of object sliding down ramp

So I think I am confusing myself about forces. I know that when something is sliding down a ramp that it will have the force of gravity, normal force and force of friction acting on it. But for an ...
1
vote
1answer
40 views

A Question on Friction [closed]

And yes, this is not a homework thing.Here's my working.
1
vote
1answer
50 views

Why two colliding bodies exert varying forces on each other during the course of their collison?

Suppose a bat hits a ball .What is the explanation of why the force is not constant during the course of the collison. At certain instants both ball and bat exert varying degrees of force on each ...
1
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1answer
69 views

Movement and Rotation of a Inverted-Pendulum-like Object with External Forces

I'm struggling to model the movement of a complex object based on an external force. Let's start with a simple example of what I'm looking for. We have a block $b$ of mass $M_b$, moving ...
3
votes
1answer
72 views

Could the 4 Forces Split Off or “Decay” into Other Forces in the Distant Future? [duplicate]

From my basic understanding of popular-level physics articles and books and such, the 4 forces (Electromagnetism, Gravity, Strong and Weak Force) used to be 1 force in the early universe, then split ...
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2answers
174 views

Can the coefficient of friction be derived from fundamentals?

It is common to want to derive macroscopic laws from what we know microscopically - after all, given a (correct) microscopic description, everything larger should follow. Has it ever been done to ...
2
votes
1answer
59 views

To which side will it move? [closed]

Children pull the carousel with diverse forces (as in the picture below). In which direction will the carousel move? Calculate the torque. I have done the following: The torque of the force that ...
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vote
2answers
102 views

Why does a reaction force still allow the thing exerting the force to move?

A $5$ kg and a $10$ kg box are touching each other. A $45N$ horizontal force is applied to the $5$kg box in order to accelerate both boxes across the floor. Ignore friction forces and ...
4
votes
1answer
127 views

You are trapped on a frictionless sheet of ice. Can you escape by inhaling in one direction, then exhaling in the opposite direction?

You are trapped on a frictionless sheet of ice. If you trued to escape by blowing, you would have to inhale eventually, which would counteract the force you gained by blowing. However, if you were to ...
1
vote
3answers
88 views

Why can't I harness normal force?

Lets say I have my palm flat with a book resting on top of it, and I have my feet on the ground. I extend my arm so that now it's kind of difficult to keep the book up. Why doesn't my hand just ...
1
vote
1answer
56 views

Rigid body: internal work null?

I am following an elementary physics course book, namely W.E. Gettys, F.J. Keller and M.J. Skove's Physics (in an Italian translation). In exercises where no non-conservative force acts on a rigid ...
6
votes
1answer
141 views

Analysis of a card pyramid

Here's an interesting question I thought of. Firstly, picture one of those card pyramids. Hopefully you know what I'm taking about when I say card pyramid, but basically you balance two cards up ...
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2answers
51 views

Describing forces mathematically

Let's say you wanted to write a differential equation for the forces acting on an orange sitting on the table (or any other object) using Newton's second law. Somehow you would have to add up all the ...
3
votes
1answer
74 views

Determining straining force and reaction forces on a beam [closed]

A homogenous beam $OA$ with the length $4a$ and the mass $m$ can rotate in the vertical plane along a horizontal axis through $O$ and is kept in equilibrium by a wire running from the points A and C ...
1
vote
3answers
71 views

The speed of air rising through a heated tube

I would like to get an explanations of an observed physical phenomena. When a metal tube is placed vertically and heated and the air inside rises, the speed of the air moving through the tube ...
14
votes
6answers
3k views

Can you ever exert more downwards force than your weight?

So, because I'm a hardcore person, I risked all this afternoon by going out in the wind, the rain and the cold to construct a willow den. Yes, it seems a menial task, but it was actually quite ...
2
votes
1answer
44 views

Distribution forces

I've got two trees and between them is a rope. When someone about 100kg sits at the center of the rope, what are the forces on both parts of rope (to the left-hand side from the person and right-hand ...
1
vote
1answer
62 views

Where should five charges be placed inside a hollow sphere so as the system has the lowest potential energy? [duplicate]

I want to know the configuration where the system would be most stable.I only know basic Physics & Maths and cannot start solving the problem.I can understand it for 4 charges and 6 charges as a ...
0
votes
3answers
83 views

On a scale, why does the heavier object go down?

When you balance a pencil on your finger, I have always wondered, "Why does the heavier part go down, and the lighter, up?"
1
vote
1answer
90 views

Could time be considered a force

I think I understand the basic concept of spacetime, at least some of it. And when people talk about spacetime they don't call gravity a force, but rather the result of mass interacting with it. And ...
2
votes
0answers
47 views

Particle moving under force $F=-cx^3$ [closed]

A particle with mass $m$ moves under influence of a force $F=-cx^3$, with $c$ a constant. What is the potential energy function $V(x)$? And if it starts to move from rest from position $x=-a$, what ...
0
votes
1answer
56 views

Does gravity (and all other fundamental forces, for that matter) have infinite energy as they seemingly last forever? [duplicate]

If I put a brick onto an steel platform, that platform can hold the brick A LONG TIME, if not FOREVER. Does the platform exert force? If so, then shouldn't it have infinite energy to resist the pull ...
0
votes
1answer
51 views

How can light experience a force [duplicate]

According to the second law of Newton f=ma only objects with mass can experience a force. But light can be bent by gravity and is not supposed to have a mass. How ...
0
votes
1answer
24 views

What is the long-term effect of a continuous off-set force, acting in a frictionless environment?

An example would be if a satellite had a rocket on one edge, which were to fire continuously. I can see that there will be both lateral and rotational acceleration, but what I am less clear on is ...
0
votes
1answer
82 views

Speed, weight and force [closed]

If a road roller of weight $W$ is rolling on the road at the speed of $X\,\mathrm{kmph}$, how much force does it apply on the surface of the road (considering a sampled surface of the same size as ...
3
votes
2answers
117 views

What is the maximum net force of surface tension per gram of water?

I've always wondered how much force water exerted through surface tension. By maximum I mean the theoretical pulling/attracting power. Also, what would happen if you raised or lowered the power? ...
0
votes
1answer
19 views

Superposition of accelerations in multibody problem

I am currently trying to design a game that implements Newtonian gravity, and am trying to code something that draws the trajectory of a small mass being acted upon by the gravity of much larger ...
1
vote
0answers
89 views

Why is gravity so weak? [duplicate]

How does physics explain the enormous disparity between the gravitational scale and the typical mass scale of the elementary particles? In other words, why is gravity so much weaker than the other ...
2
votes
2answers
65 views

Why does the period/frequency of a fan slow down significantly when I taped a piece of rubber band to it?

All of this was done with a standing fan set horizontally on a table. During an experiment, I had to tape a piece of rubber band to one of the standing fan's blade and measured the period of the fan. ...