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
votes
2answers
32 views

Pressure exerted by a gas and the ideal gas equation

While determining the pressure exerted by any gas at a temperature why do we not consider the surface area of the container in which it is kept? We say that : P=nRT/V, where, n is the no. of moles, R ...
0
votes
1answer
35 views

normal force on a physical pendulum

I have read and understood that a normal force has got nothing to do with torque on a physical pendulum. But I can't understand in which direction the normal force points to. Can someone help? This ...
1
vote
1answer
44 views

Question about inertial mass and gravitational mass

I know that inertial mass $m_i$ is the quantity that appears in Newton's second law: $F=m_ia$ and that gravitational mass $m_{g_1}$ is the quantity that appears in Newton's gravitational law: ...
3
votes
2answers
61 views

Force against mg when block is connected to block and held horizontally

In the image attached, what would be the force that would balance out the gravitational force $mg$? The block is also not accelerating downwards so there should be some force acting on the block to ...
-1
votes
1answer
20 views

External and internal resistance to airflow

If an aircraft was travelling at 100mph an hole was opened to allow 100mph into the cabin,then the airflow is feed into an amplifier like a ramjet and the airflow out of the ramjet was increased to ...
5
votes
4answers
130 views

Rotating the bucket in circular motion without spilling water

In the bucket experiment when the bucket reaches the top of the circle why will it have a normal force acting on the water downwards? Doesn't normal force oppose any other force? There is no force ...
-1
votes
0answers
16 views

what is the reaction force of electromagnetic force created on a conductor in a magnetic field? [on hold]

If a force is created on a conductor carrying a current in a magnetic field, what does the reaction of this force act on?
32
votes
7answers
5k views

Supergun Launching of Satellites

I should say first that I don't believe this is a feasible launch method, otherwise NASA and other space agencies would be using it by now. It's based on this BBC news story Saddam Hussein's Supergun ...
0
votes
1answer
46 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 ...
-1
votes
1answer
28 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. ...
1
vote
1answer
40 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" ...
0
votes
0answers
65 views

Cavendish Experiment [on hold]

Would the earth’s gravity overpower the gravity of the much smaller and less dense lead spheres?
0
votes
0answers
26 views

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

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 ...
0
votes
1answer
42 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 ...
0
votes
2answers
39 views

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

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. ...
0
votes
1answer
31 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\{ ...
1
vote
2answers
13 views

Difference in Energy Transfer Between Impacts and Nudges [on hold]

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 ...
1
vote
1answer
56 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 ...
3
votes
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 ...
1
vote
0answers
48 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 ...
-1
votes
0answers
26 views

How one fly using allomancy? [closed]

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 ...
0
votes
0answers
25 views

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

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 ...
0
votes
0answers
19 views

Vertical Scale Acceleration Values [closed]

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
0answers
68 views

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

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) ...
3
votes
0answers
48 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 ...
-1
votes
0answers
26 views

What is the horizontal acceleration of the block? [closed]

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 ...
1
vote
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 ...
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 ...
0
votes
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
2answers
62 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 ...
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 ...
1
vote
2answers
69 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 ...
-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 ...
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 ...
1
vote
1answer
64 views

Does Newton's third law remain totally unchanged even in Einstein's theory?

Why Newton's third law remain unchanged still now in relativity theory (as for example that is why we feel weight due to equal but opposite reaction of the Earth's surface)?
1
vote
2answers
72 views

How do we define what is “External” force or “Internal” force in the context of momentum conservation?

I know that without presence of any "External" force momentum is always conserved. But how do we distinguish between "External" force and "Internal" force where all are "Force"?
0
votes
2answers
33 views

How to prove that the potential of a conservative central force depends only on the magnitude of the distance & not on the direction of the vector?

If a conservative central force acts on a body then its potential only depends on the magnitude of the distance between two bodies (does not depend on direction of vector). Is there any proof of it ...
0
votes
0answers
53 views

Why Newton's gravitational constant remains unchanged in relativity though gravity is not a force?

I know that Einstein described gravity as a curvature of spacetime. So, It is not a "force" but why Einstein had to accept Newton's gravitational force constant?
0
votes
1answer
27 views

Torque on a charged ring

I have been studying electromagnetic induction. As I understand, a magnetic field will exert a force on a moving charge. What I would like to know is whether a changing magnetic field will exert a ...
0
votes
0answers
16 views

Spring constant of a union of springs - Why is it so? [duplicate]

As I was learning about springs, I bumped into a theory saying that if we take one, long spring and divide it (cut) into, let's say, two springs of the same length, their spring constant will be $k = ...
0
votes
4answers
92 views

Why the pressure in liquids only depends on the height?

look at this picture : and also look at this one: imagine that the surface area of both is the same and both of them are full of water. My question is that why they both are pressing the beneath ...
0
votes
0answers
27 views

Adding multiple torque vectors together to determine resultant torque

I am working in a 2D environment, where there are multiple angular forces (torque) applied at an object. The way I calculated 1 torque "application", was by: ...
2
votes
4answers
122 views

Is this Coriolis Force explanation simplified?

As air moves from high to low pressure in the northern hemisphere, it is deflected to the right by the Coriolis force They use an example of a merry-go-round, which makes sense intuitively. An ...
0
votes
1answer
43 views

Does momentum scale linearly with time, assuming a constant nonzero net force, even at relativistic speeds?

I would expect it to, since you'd think the loss of velocity due to relativity would be made up for by the gain in relativistic mass. I'd like this to be confirmed, though. and if so, in whose ...
1
vote
1answer
72 views

Why a bullet leaves a hole on glass where stone makes scratch?

When we throw a stone it breaks the glass with scratches. But when a bullet hits the glass it leaves a small hole(not always) . I want to know the specific reason behind making hole and scratch.
1
vote
1answer
15 views

Power needed to raise a bucket at a constant speed by a pulley

This is the last section of this pulley exercise: The bucket in is filled with water so its total mass is now $45$ kg. The bucket is raised at a constant speed of $2.0$ $ms^{-1}$ using an ...
0
votes
2answers
28 views

If a block moves on a straight line (no friction) for time $T$ and then along an incline plane, what will the displacement vs. time graph look like?

In my opinion, the graph for the first part of the motion will be a straight line passing thorugh the origin (at the beiginning of motion) and then it will be a falling parabolic curve ( $x$ is ...
1
vote
3answers
110 views

How does the Electric Field create a force? [closed]

If we have 2 charged particles which are a certain distance away from each other, they either attract of repel due to the electric field created by both of them. But I don't understand the mechanism ...
1
vote
0answers
39 views

Why we can use partial derivatives to tell if a force is conservative? [duplicate]

Let us, initially, analysis only a two dimension situation. Assume that $F(x,y)$ is a force dependent on the particle position (give by $x,y$) is proposed that if \begin{equation} \frac{\partial ...
0
votes
1answer
46 views

Are all forces given by a field conservative forces?

When teaching us electromagnetism, our professor first introduced us to the concept of "field". Several lessons later, he proved that electric field force is a conservative force. But I think the ...