# Questions tagged [forces]

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 the [particle-physics] tag for decay channels due to forces and [newtonian-mechanics] or one of the other subtopics of [classical-mechanics] for the dynamics of classical systems.

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### Force problem related to adhesive and bonding

I have two PCBs (printed circuit board), and they are glued by adhesives, as show in the pictures. And the location of the adhesives are indicated on the picture (please notice that NO adhesive is ...
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### Minimum velocity required to "skip" a spacecraft across the atmosphere?

When, hopefully, Virgin Galactic spacecraft start regular operations in a few years, they will be simply travelling upwards, then achieving weightlessness for a short while, followed by a return ...
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### How to calculate the required force to from lever to pushrod in order to close calliper in a hydraulic braking system?

How to calculate the required force to from lever to pushrod in order to close calliper in a hydraulic braking system? Through test and data i have determined the average force on a bicycle lever is ...
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### Reaction force exerted by pulley's support

Consider an in-extensible string passing over an ideal pulley connected to a block of mass $m$ as shown: The ends are pulled with a force $F$ Am I correct in saying that the block will experience a ...
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### 3-force in General Relativity

Let's consider the definition of 3-force in different theories: Newtonian mechanics In Newtonian mechanics, we can define the force as a cause of changing momentum $p=m\vec{v}$ with time. According ...
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### Calculating forces via Feynman diagrams?

How would one go about calculating forces that test objects feel using Feynman diagram methods? For example, say we have a massive object in GR so that the metric takes on the standard Schwarzschild ...
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### Will the beaker be acted upon by the force in the direction of the green arrow?

The black circle is the top view of the beaker. In the gravity field, the beaker is vertical down along the beaker axis. The beaker is still. The water in the beaker rotates at a uniform angular speed ...
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### Table on inclined plane - normal force

So, I'm struggling to understand how the normal force works in case of the inclined plane. It's obvious for me what happens if the body is, for instance, a block or a cylinder, however, I can't got ...
208 views

### Applying an external force from inside a ball

I know that to accelerate an object we have to apply an EXTERNAL unbalanced force. I thought about the following situation. I am inside a large transparent ball. I want the ball to move forward. I ...
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### Force balance for belt-pulley-mass model (2nd order response system)

I am trying to model a mass being driven by a motor (Angular acceleration $\dot{\omega}$ and shaft-polar modulus $J$) with belts and pulleys. This is then being compared to numerical simulations. I ...
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### What does Newton's third law actually look like with a finite speed of causality?

Newton's third law of motion states (as quoted on wikipedia): When one body exerts a force on a second body, the second body simultaneously exerts a force equal in magnitude and opposite in direction ...
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### Newtons law of gravity from Wilson loops?

Wilson Loops in Quantum field theory $W_\gamma = trPexp(\int_0^1 dt \dot\gamma_\mu A^\mu)$ for curve $\gamma(t)$ and Connection $A^\mu$ are used to define an effective force law of a theory in a ...
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### Could a hydrophobic surface increase a liquid's resistance to compression/displacement?

Imagine a quantity of an aqueous (yet slightly viscous) solution is resting on a hydrophobic surface with a contact angle around 100°. A downward force is then applied as a (repellant) surface is ...
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### On the infinite range of the electromagnetic force

I am curious as to whether there is a fundamental reason why weak and strong nuclear forces have such a short range whereas gravity and the electromagnetic force seem to have infinite range. Since ...
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### Proof of principle of transmissibility of force

The principle of transmissibility states The point of application of a force to a rigid body can be moved anywhere along its line of action without changing the external reaction forces. My question ...
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### Surface tension of a fluid

I understand that there is an imbalance of forces between molecules that lie on the surface of a fluid compared to those that lie within. This results in the surface area is minimised. However, I can'...
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### Mechanics of ''Sumo'' vs Conventional Deadlift

A classic strength move (called the deadlift) involves bending over a heavy bar, holding it in one's hands, and then pulling it off the floor and standing up straight. Recently a variant called ''sumo ...
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### Microscopic description of drag

It is well known that a fluid opposes the motion of a moving object and we can represent this resistance in motion with a force, which we call it drag. Different fluids exert different drag forces ...
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