# Tagged Questions

General questions about the way objects move and interact. This tag should be used when the tags for certain kinds of mechanics (newtonian-mechanics, classical-mechanics, quantum-mechanics, etc.) are too specific.

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### sending information over a wire--mechanically [duplicate]

Possible Duplicate: Is it possible for information to be transmitted faster than light? I've thought about this since I was a little kid. I know it isn't exactly feasible, but it still ...
115 views

### Best book for learning sensor fusion, specifically regarding IMU and GPS integration [closed]

I have a requirement of building an Inertial Measurement Unit (IMU) from the following sensors: Accelerometer Gyroscope Magnetometer I must integrate this data to derive the attitude of the sensor ...
361 views

### Classical Mechanics for Mathematician [duplicate]

Possible Duplicate: Which Mechanics book is the best for beginner in math major? I am looking for suitable ways to learn mechanics in mathematician's perspective. I went through: ...
685 views

### How do levers amplify forces?

This is really bothering me for a long time, because the math is easy to do, but it's still unintuitive for me. I understand the "law of the lever" and I can do the math and use the torques, or ...
327 views

### Will tensile strength keep a cable from snapping indefinitely?

Trying to secure a wall hanging using magnets; me and a coworker came up with an interesting question: When the hanging is hung using 1 magnet, the weight of it causes it to quickly drag the ...
1k views

### A spinning bullet

I know the rifling in a gun or rifle puts a spin on the bullet along the axis of trajectory. Now I don’t understand exactly what does it make the trajectory more stable and the travel grater?
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### What is the mathematical formulation for buckling?

Argument: Buckling is an engineering concept that can only be applied to thin columns with compressive loading. (Is it possible to) Prove the above sentence right or wrong with mathematical ...
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### Is there analysis library for stress-strain data?

I have three column data that has time-displacement-force from 1D tensile/compression test. Now I would like to get the standard mechanical properties of the material, like Young modulus, yield ...
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### Shape of rotating rope (lasso problem?)

Let's take a wire or a rope. I usually do this with a chain or my scarf. I fixate one end in my hand and apply rotation (by subtle movements of this endpoint like spinning a lasso). The rope gets ...
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### Hamiltonian of a water molecule bounded to a surface

Where can I find a way to construct the hamiltonian of a water molecule bounded to a surface? More generally,how can one write the hamiltonian of an atom bounded to a surface?
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### How to find the value of the parameter a in this transfer function? [duplicate]

Possible Duplicate: How to find the value of the parameter $a$ in this transfer function? I am given a transfer function of a second-order system as: $$G(s)=\frac{a}{s^{2}+4s+a}$$ and I ...
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### How to find the value of the parameter $a$ in this transfer function?

I am given a transfer function of a second-order system as: $$G(s)=\frac{a}{s^{2}+4s+a}$$ and I need to find the value of the parameter $a$ that will make the damping coefficient $\zeta=.7$. I am not ...
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### Confused with stress, strain and linear thermal expansion

Four rods A, B, C, D of same length and material but of different radii r, 2r , 3r and 4r respectively are held between two rigid walls. The temperature of all rods is increased by same ...
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### Why is the optimum wheel size of a bicycle about the same as that of a car?

The optimum wheel diameter of cars and bikes appear to be roughly the same, certainly well within an order of magnitude. This is despite very different average speeds and propulsion mechanisms. Can ...
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### Acceleration: Value Disparity?

If we consider a ball moving at an acceleration of $5ms^{-2}$, over a time of 4 seconds, the distance covered by the ball in the first second is $5m$. In the 2nd second will $5 + 5 = 10m$. In the ...
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### How equivalent are heat energy and work energy in connection with a spinning flywheel?

Let's say we have two identical spinning flywheels, that have arbitrary geometry, and are made of copper. Now we apply some heat energy at the center point of flywheel A, causing it to slow down a ...
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### Does a straight water hose issue water at a greater pressure than a Coiled water hose of same diameter and length?

I have a one BHP water pump, the water pressure of a coiled hose connected to the water pump output side was not that great. Would an unwound water hose produce greater water pressure? [Friction ...
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### Is there symmetry in 2d stress tensor in linear elastic fracture mechanics?

Assumptions: Cross terms in strain tensor are defined as equal $\varepsilon_{xy} = \varepsilon_{yx}$. pure mode I crack. Far from crack tip, material is purely elastic and we are way below yield ...
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### Dynamo-meter and forces problem [closed]

I have this system: Where D stands for dynamo-meter, and you can exclude all lines\dynamo-meters\balls weight and friction. The left ball connects to body A, and the right ball connets to the wall. ...
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### Why do control moment gyroscopes exhibit “torque amplification”?

There are a number of articles that describe the benefits of using control moment gyroscopes (CMGs) over reaction wheels in inertial navigation applications. One of the primary benefits of using a CMG ...
1k views

### Work done by spring over distance

I'm working through a problem involving energy conservation. Unfortunately, I cannot calculate the work done by a spring. ...
135 views

### Distance a curveball travels?

I've seen some discussions regarding the movement of a spinning object, say a curveball. However, all have been largely qualitative. I was wondering if anyone has seen or worked through a ...
293 views

### Does the potential energy of fluid rising on a string change?

Lets say I have a glass of water at rest. Then I go and hang a string above the water (vertically), such as the end of the string is immersed in the water. Over time some of the water is going to ...
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### Conjugate Variables and Fourier Transforms in Classical Physics

Let q be a generalized coordinate with a conjugate momentum p and a potential resulting in a periodic motion of q. What is the meaning of the Fourier transform of q(t) over its period? Can this be ...
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### Trace the path for the following case [closed]

2 identical balls 1m apart are moving in such a way that they are rotation around each other with same speed. Trace the path followed by them.
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### Determine the tensor of contraint and deformation of a cube under compression

We have a cube under compression with dimension l1*l2*l3, is put between 2 rigid plates in the axis 1 (two plates block the deformation of the cube in thí axis), the cube is also put on a rigid plate, ...
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### Spin angular momentum of a system of particles : Is there any energy associated with it?

Consider a system of point particles , where the mass of particle $i$ is $μ_i$ and its position vector is $\vec{r}_i$. Let $\vec{r}_\text{cm}$ is the position vector of the center of mass of the ...
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### What are the expressions for rotational and translational kinetic energies of a system of point particles?

Consider a system of point particles , where the mass of particle $i$ is $\mu_i$ and its position vector is $r_i$. What are the expressions for translational kinetic energy and rotational kinetic ...
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### I think there is something wrong with this problem. How do you know if the vertical acceleration is zero?

Suppose a block with mass 3kg is on a frictionless table and a force of 15N pulls it from an angle of 38 degrees above the horizontal. 1) What is the apparent weight of the block? 2) What is the ...
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### Calculating stress without strain

I am working on an algorithm for a real-time simulation. I would like to calculate to extremely permissive tolerances approximate values for the stress within a 2D geometry. It will not be difficult ...
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### Studying from “Berkeley Physics Course Volume I - Mechanics”

I'm a first year physics student and the main source for our Physics I course is "Berkeley Physics Course - Volume I." I'm having a hard time understanding this book because it assumes a pretty high ...
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### How should a closed-ended terrestrial trajectory be corrected for the Coriolis effect?

I have tried verifying the numerical integration of the Coriolis effect for 1000 to 2000-yard rifle fire by switching ON/OFF the Coriolis correction of a good ballistic simulator program (PRODAS). The ...
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### Cheetah prosthesis efficiency

I want to compare the much-talked about Cheeta running prosthesis to a the normal running process in terms of force and energy, but I don't know where to start. How would you start the comparison? A ...
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### Do we know how matter moves matter?

I was surprised when reading an apologetics book recently that attempted a rebuttal of the claim that "An immaterial mind cannot interact with the physical order." Here was the response: How could ...
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### How fast does force propagate through matter? [duplicate]

Possible Duplicate: Is it possible for information to be transmitted faster than light? Consider the following thought experiment. You have a long perfectly rigid beam (for the sake of ...
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### centrifugal force in static frame of reference

The other day we derived Kepler's third law. $$\left( \frac{T_1}{T_2} \right)^2 = \left( \frac{r_1}{r_2} \right) ^3$$ In order to derive this, you can look at a given planet that revolves around ...
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### Error caused by pulley eccentricity [closed]

Not sure if this is perfectly a physics question: A rope is wrapped around a cylinder of diameter D. The cylinder is slightly eccentric so that the distance between the axis of the cylinder and the ...
359 views

### Is instantaneous velocity an abstraction?

In introductory analysis, the discussion the derivative emphasizes that while average rates of change are measurable, instantaneous rates of change are a "limiting abstraction". While this makes ...
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### Does a thermally expanding torus experience internal stress?

I'm trying to learn continuum mechanics and thermo-mechanics. As we know, heating an object increases the mean atomic distance $a_0$ of the atoms in a rigid body. Let's assume it is a linear elastic ...
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### Force on rope with accelerating mass on pulley

I have a pretty basic pulley problem where I lack the right start. A child sits on a seat which is held by a rope going to a cable roll (attached to a tree) and back into the kid's hands. When it ...
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### Movement of a nudged block on a high friction surface

If I apply a single force to an object ‘floating in free space’, then it will either translate (if the force is in line with the Cof G ) or more generally it‘ll rotate about the C of G due to the ...
241 views

### How can you test to see if a dice is weighted?

I was browsing Etsy today and came across this. What tests are there to see if the dice are usable, ie, if one side isn't favored over another, and if all sides are balanced? Would this just be to ...
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### Conveyor scales modeling

Assume we have a conveyor scales. Which consists of scales, and motor with conveyor belt placed above, so that the boxes can be measured (weight) while moving above. What I want is to create the model ...
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### Flattening rate of a parabola

If you have a piece of paper that is furled and unfurled so that it's in the shape of part of a parabola, and knowing that if you leave it, it'll flatten itself after time, would it flatten faster if ...
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### Is the static gauge pressure of a free jet always atmospheric?

Let's say I have a free jet of air leaving a pipe into the atmosphere. I know that the static gauge pressure at the pipe exit is equal to the atmospheric. But what about the static gauge pressure 10 ...
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### Is the pressure at the outer hole on a pitot static tube equal to atmospheric pressure?

I'm looking at a pitot static tube question right now and I just need some clarification. There is the outer hole on the pitot static tube, not the hole that the air stream goes through, but the other ...
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### How do I determine where the maximum air velocity around an object is?

I have a freestream of air directed at an object. Is there a way to find where the maximum air velcoty occurs with only having initial air speed and static pressure at the object?
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### How must you spin the ball to make it alternate between 2 positions? [closed]

Assume any parameters you may need. Thanks in advance.