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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-3
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0answers
23 views

Is this correct?

Yes, these are hands. No, i'm not good at drawing If the muscles of one hand are pushing with $100N$ and the other with $200N$, at the contact, due to Newton's third law, the force acting on both ...
0
votes
1answer
18 views

Why are upthrust and normal reaction force not the same?

I am currently studying IGCSE Physics, and have the following question: Why aren't upthrust and normal reaction force not the same. I understand that upthrust only occurs in fluids, and normal ...
0
votes
1answer
19 views

Why is force negative if PE increases?

I'm looking at the PE vs force graphs for gravity, and it doesn't make sense to me. As potential energy increases (and the object goes higher above the ground), F=-mg. But if I'm raising an object up, ...
0
votes
1answer
35 views

Working Out Shaft Torque in a Stirred Tank with a Cylindrical Cavern Formation (using a non Newtonian fluid)

Here is some background to the problem (in a stirred tank): "With yield stress non-Newtonian (viscoplastic) fluids, it is possible to generate an agitated volume around the impeller, defined as a ...
0
votes
0answers
17 views

Calculating impact force of steel tip darts for soundproofing

I'm trying to soundproof a dartboard by mounting it with silicone gel vibration mounts. I'm having trouble selecting anything though because I need to know what kind of forces I'm trying to mitigate. ...
-2
votes
1answer
59 views

What does $P = Fv$ mean? [on hold]

The engine of a car is developing a power of 90kW when it is moving on a horizontal road at a constant speed of 100 km h−1. Estimate the total horizontal force opposing the motion of the car. I ...
1
vote
0answers
32 views

Newton's third law confusion [duplicate]

If A exerts a force of 200N on B, then by newton's third law, 200N would be exerted on it. Similarly, if B exerts 100N on A, by newton's third law, 100N would be exerted on it. Therefore the net ...
53
votes
8answers
51k views

With Newton's third law, why are things capable of moving?

I've got a rather humiliating question considering newton's third law "If an object A exterts a force on object B, then object B exerts an equal but opposite force on object A" -> $F_1=-F_2$ ...
0
votes
2answers
451 views

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 ...
1
vote
2answers
31 views

Centripetal force and friction

Here is the question I need help on: A hemispherical pile of snow with a height of 20 m is piled up. An extreme skier starts at the top of this snowball, and she skies down finding that ...
1
vote
1answer
119 views

Disk and Ball on a smooth surface [closed]

A uniform disk of mass $\text{2m}$ and radius $\text{R}$ is placed freely on a smooth surface as shown in the figure. A particle of mass $\text{m}$ is connected to the circumference of the disc with a ...
0
votes
0answers
18 views

How to calculate maximum magnetic flux density of magnet?

I have some magnets of which I need to calculate the maximum magnetic flux density B. I don't have any dedicated setup to measure the value. Is there any way in which I can measure it by relating it ...
0
votes
1answer
156 views

Negative Sign in Compression Modulus

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 ...
-2
votes
2answers
41 views

Condition for a particle to move on a sphere

Is it possible for a particle of mass $m$ to complete a circular path on a sphere if it starts from the topmost point and no external force acts on it except gravity and frictional force between ...
-6
votes
0answers
30 views
-1
votes
1answer
29 views
0
votes
1answer
44 views

Can drag force and lift force be in the same direction in the following case?

In the attached picture, can I say that there is a lift force in the Y-direction, and a drag force too in the same Y-direction? $F_L$ proportional to $V_fx^2$ ? $F_D$ proportional to $V_py^2$ ? Is ...
0
votes
0answers
21 views

Will the force acting be doubled? [duplicate]

If me and a man are holding a string, and I apply a force of 100N, the tension in the string would be 100N, and it would exert a 100N force on the man and an equal and opposite force of 100N on me. ...
3
votes
1answer
240 views

Force field for calcium ions, potassium ions and water in molecular dynamics

I want to adapt my existing MD simulation so that it can handle these three species. For the interactions of the ions I thought that I would use the coulomb potential, but I don't know what sort of ...
23
votes
3answers
2k views

Why doesn't a fly fall off the wall?

Pretty simple question, but not an obvious answer at least not to me. I mean you can't just place a dead fly on the wall and expect it to stay there, he will fall off due to gravity. At first I ...
0
votes
0answers
49 views

The force of gravitation [on hold]

Which is greater: attraction of the Earth to 5 kg of iron or attraction of 5 kg of iron to the Earth? give reasons. When an apple falls towards the Earth, the Earth moves up to meet the earth. Is ...
0
votes
2answers
3k views

The direction of frictional force in smooth rolling motion

I want to ask about the direction of frictional force in smooth rolling motion which means the rolling object doesn't slide on the surface. Here is the first case, the wheel rolls to the right so the ...
-2
votes
0answers
28 views

BASED ON NEWTON'S 3RD LAW [duplicate]

my question is based on newton's 3rd law . An elephant pushes a rabbit with $250 N$ force , then the rabbit should also apply $250 N$ force but the rabbit is only capable to apply $25 N$ force . Why ...
0
votes
1answer
229 views

How is Magnetic force on a current carrying conductor $Blb$

I was reading an answer about torque acting on a rectangular current carrying loop kept in a uniform magnitude field B. Force acting on each sides is $F_1$, $F_2$, $F_3$, $F_4$. It's written here : ...
0
votes
1answer
25 views

How to calculate impulse required to move an object vertically upward by given distance [on hold]

Suppose I have a stationary object of mass $m$ and I want to apply a momentary force in the vertical direction so that it just reaches the height $h$. So how do I calculate the impulse required in ...
7
votes
5answers
928 views

How does water carve rock?

How does water carve rock? And more generally, how does a soft material carve a hard material? Obviously it happens, but is it a continual process (every drop of soft water carries away a minute ...
3
votes
3answers
94 views

Is static friction the only force causing a car to move (without sliding)?

A car is moving without sliding means that the friction between wheels and the ground is static friction. This is the force causing an object to move forward, therefore, its direction is the same as ...
0
votes
1answer
38 views

Force of Electrostatic Attraction between 2 rings

Before someone puts it on 'hold' , this is not a homework question, I doubt you'll find it somewhere as I thought of it. I wish to find force of electrostatic attraction between 2 uniform rings of ...
-1
votes
1answer
23 views

Net force equal to mass multiplied by acceleration of centre of mass [closed]

$F=ma$ if $a=0$ then definitely the net force applied will be also zero (0). then, in this case $m=F/a$. If both net force and acceleration(of centre of mass) is equal to zero (0). then, isn't mass ...
0
votes
0answers
25 views

Force Of Attraction between 2 rings [closed]

We have 2 rings of say equal radii (for simplicity) separated by a distance d. I ring carries +q charge and the other -q. I wish to compute the electrostatic force of attraction between these. Is it ...
1
vote
3answers
34 views

Is drag force in the direction of particle motion or opposite to motion?

Suppose water is flowing in horizontal direction (positive $x$-direction) and a particle immersed in that water is also moving in the same direction. In this case, is the drag force $F_D$ in the ...
-3
votes
0answers
32 views

physics thermofluid mechanics pressure force area [on hold]

As shown in the attached image, a tank has an inclined wall at an angle of $45^{\circ}$ to the horizontal. On this wall, there is a 1 m square door that is hinged at A and has a simple latch at B. The ...
2
votes
2answers
126 views

How does force transmit through a solid block?

If you take a solid block, say, a cube of side length $l$ with density $\rho$, you place it upon a solid floor, and you apply an external pressure of $p(x,y)$ on the upper face ($x$ and $y$ define a ...
1
vote
3answers
302 views

Finding the acceleration of a mass/pulley system without knowing the direction of the displacement

I have the following question: I noticed that if I solve for the acceleration assuming that the acceleration is occuring to the left, I get the equation: $\displaystyle a = ...
10
votes
5answers
2k views

Why don't we use the concept of force in quantum mechanics?

I'm a quarter of the way towards finishing a basic quantum mechanics course, and I see no mention of force, after having done the 1-D Schrodinger equation for a free particle, particle in an ...
2
votes
1answer
307 views

Force due to combination of free space and dielectric

I will make a generalized form of my question. There are two point charges $q$, $x$ distance apart. And there is a dielectric slab of thickness $t$ and of dielectric constant $K$. Should the force ...
0
votes
1answer
45 views

Thermofluid mechanics inclined plane

As shown in the attacked image, a tank has an inclined wall at an angle of 450 to the horizontal. On this wall, there is a 1m square door that is hinged at A and has a simple latch at B. The distance ...
0
votes
3answers
36 views

Components of gravity in an inclined plane

The reason the block accelerates down the inclined plane is that the resultant of $N$ and $mg$ acts down the incline. However, why is the force causing the block to accelerate down the incline often ...
3
votes
1answer
29 views

Bent capillary tube

What would happen if I bend a capillary tube and use it as shown in figure? 1.Will the water(or any other adhesive liquid) level remain same as before bending? 2.or it will come up till end? 3.Or ...
-2
votes
1answer
47 views

Net acceleration of an object if too many forces are acting on it? [closed]

Consider an object thrown upward with a force which is much greater than its weight. Obviously the object will stop after a certain interval of time due to air resistance. But what if there is no air ...
1
vote
0answers
11 views

Net force of a falling down people by Resolution of Force. [closed]

From the picture, I want to calculate the Force (F) when people fall down. I searched the internet, but I have no findings. Given that Mass (M) = 75 kg, Gravitational force (G) = 9.81 N. How can I ...
3
votes
3answers
29 views

Work done on an object by the internal forces

How is the work done by the internal forces acting in a rigid body zero? Actually I read in a book an example for the same. Let me present that example here. Consider a rigid body having two ...
4
votes
3answers
75 views

How do I find the relation between the accelerations of the ring and the disc (see image)? [closed]

What is the relation between the accelerations of the ring and the disc (see image)? Both the ring and the disc have mass $M$. The ring has a radius $R$ and disc has radius $2R$. They are connected ...
5
votes
3answers
82 views

Physical explanation of Pascal’s Law

I have a problem with physical explanation of Pascal’s Law. For example, when I was teaching my sister (a high school student) about force transmitting by a rope, I said her: “In a very simplified ...
2
votes
1answer
45 views

Does deformation due to a force affect the acceleration produced by it? [closed]

You have two same masses, one non-deformable and the other plastically deformable. You exert the same force for same time. Will they move with the same speed? Obviously the one will deform and move, ...
0
votes
1answer
323 views

Force between two solenoids

How does one calculate the magnetic force between two coaxial solenoids, placed in a way their currents are in the same sense? There is a simple way to treat both as dipoles and then calculate the ...
0
votes
2answers
4k views

Exactly how much lift is needed to overcome the weight of an average person?

I am designing a "glider" of sorts, and I have some basic questions about the physics involved to get me started. How much lift is required to overcome the weight of an average person, say 150 pounds? ...
0
votes
0answers
22 views

What are the calculations specifically needed for High Altitude Ballooning? [closed]

I want to know the lifting gas needed to launch the vehicle including the positive lift I want to predict the possible retrieval site I want to know the burst altitude AND MAYBE ALL WITHOUT ...
0
votes
2answers
53 views

Why an impact exerts so much force? [on hold]

If an object of velocity $v$ and mass $m$ moves towards a resting object of mass $M$, then if the object which is hit might break. Why? What is the reason that a collision has more power than a ...