Questions related to the Continuum Mechanics Division of Elasticity. The bending of beams, deflection of rods, or in general, applications of Hooke's Law generalized to three dimensions.

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Decomposition of elastic constants of a crystalline material

I have performed a calculation the tensor of elastic constants (or stiffness tensor) for a given crystalline material. From there, I calculated various elastic properties, such as Young’s modulus, ...
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384 views

Slackline Jump Tension

So a slackline is basically a bouncy tight rope. I found a site that has a calculator for the tension of a static slackline http://www.slacklineexpress.com/force.php?linelength=40&sag=1&w=...
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4answers
2k views

Hooke's law limitation question

Let's consider a spring. I am a strong man(well, lets assume) and I am pulling the spring. the work I do is being stored in the spring in the form of its elastic potential energy. Then suddenly, ...
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3answers
160 views

What is the net force experienced (at the lowest point) by a wire being rotated in a vertical circle with a mass 'm' at its free end?

A metallic wire is being rotated in a vertical circle with a mass $m$ fastened to its end. My understanding says that the net force experienced by this mass should be the centripetal force: $T - mg =...
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1answer
123 views

Will a tug-of-war battle damage my climbing rope

I plan to organize a big tug-of-war with a climbing rope (70m long) with 50-60 adults. I know the climbing rope is elastic. The rope resistance is 9 kN when a chock occurs. Will the rope breaks or ...
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1answer
52 views

How to reduce size of bracelets using physics?

My mom has a set of bangles (bracelets) made of gold like the ones shown in the picture. Problem is the size (diameter) of these bangles is a bit more than required. If she goes to a goldsmith he cuts ...
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2answers
176 views

Where does the energy go when you stretch a rubber band?

There is resistance when you stretch a rubber band. That makes sense to me because the energy you exert is turned into potential energy of the rubber band, but if you hold the rubber band in the same ...
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2answers
127 views

Difference between stiffness and damping?

I understand stiffness as the extent to which an object (e.g. a mass spring) resists deformation from an applied force, or the rigidity of an object. And I understand damping as the energy ...
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1answer
47 views

Does water have shear thinning property? [closed]

I'm working on a project and I need to know if the water is viscoelastic? does water have shear thinning property?
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2answers
40 views

How does my reference point affect the regresion of data about Hooke's law?

A vertical spring is used (subject to a universal support) whose length is $20$ $cm$ when no force is acting on it. We put on a weight of $1$ $N$ and the new length is $22$ $cm$. When writing the data ...
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2answers
160 views

Why don't we consider both the forces while calculating the magnitude of stress in an elastic body?

Consider a wire being stretched from two ends with equal forces. We know that both of these forces collectively participate in elongating the wire; had there been one force the wire would have ...
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1answer
78 views

How must you spin the ball to make it alternate between 2 positions? [closed]

Assume any parameters you may need. Thanks in advance.
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3answers
64 views

the poisson ratio and conservation of volume

In order to measure the Poisson ratio of a rectangular sample of elastic material I subject it to a vertical load along its major axis using weights of gradually increasing importance and measure the ...
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2answers
70 views

Estimating Young's Modulus

In order to measure the Young's modulus of a rectangular sample of elastic material I subject it to a vertical load along its major axis using weights of gradually increasing importance and measure ...
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2answers
60 views

Impulse in perfectly elastic collision

I am implementing this simplified model at the moment, and I am trying to get my head around the physics concepts behind this model. Event-Driven Simulation So the model has two parts, first is ...
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1answer
19 views

What are the assumptions made when analysing a stretched elastic string from a thermodynamic aspect?

Consider a stretched elastic string. Then conducting a thermodynamic analysis of the elastic string. The approach is very similar to that used for $(P, V, T)$ systems, with the pressure and volume ...
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1answer
25 views

Restoring force in circular rod

Can somebody explain how to calculate the restoring force in a uniform circular rod with known Young's modulus and diameter. I would need the restoring force in a specified distance from the origin ...
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1answer
101 views

Deformation of an elliptical ring

How will it deform when I compress an elliptical ring along its long axis? For simplicity we could consider that the ring is homogeneous, elastic, has no internal stress at the beginning, and its ...
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2answers
79 views

Point forces in linear elasticity and small strains

Consider a point force $\boldsymbol{F}=F\boldsymbol{e}_z$ in an infinite elastic material. In a linear approximation, the displacements can be calculated using Green's function for the Laplacian which ...
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1answer
1k views

Help calculating work done by stretching a wire [closed]

A wire of length 0.89 m and cross-sectional area 1.7 cm2 is stretched elastically by an amount 1.2 cm. By Hooke’s law, the restoring force is $−k\Delta L$. Calculate the work done in stretching ...
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2answers
100 views

Why only vertical component of the stress tensor on vertically suspended bar?

EDIT: I am gonna rephrase the question entirely. Imagine we have a bar which we will analyze in the linear elastic regime. The shape of the cross section is irrelevant. The bar is suspended from a ...
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2answers
465 views

When a wire is stretched by a load, is there any change in its volume? [closed]

When a wire, or a rod(whose diameter is not negligible) is subjected to a tensile stress, is there any change in its volume? If yes, does the volume increase or decrease? Take into consideration both ...
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2answers
284 views

How do you make a collision more elastic?

Currently, as described in this question, collisions cannot be elastic. However, is there a way to make a collision more elastic? Background: We're working on a project right now involving high ...
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2answers
1k views

Will larger balls make a Newton's cradle swing more stable?

I got a rather small Netwon's cradle and when I start it, the effect is not very good since all the balls start to swing where the effect we want is obvious. The balls are small and I wonder if larger ...
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3answers
5k views

Young's Modulus and Vibrating String Harmonics

I was wondering how Young's Modulus effects the resonant harmonics of a vibrating (string instrument) string. I know that the string's fundamental frequency is $$\frac{1}2 \times \text{Length} \times \...
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1answer
14 views

How does linear elasticity deal with Heaviside forces?

For a particular elastic material with prismatic geometry, I observed a linear relationship between stress and strain but the forces applied to the material are given by a step function where the ...
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1answer
42 views

necessary and sufficient conditions for linear elasticity

If it's experimentally observed that a particular elastic isotropic material has a linear relationship between stress and strain for a certain range of stresses and strains, does it follow that a ...
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1answer
17 views

ultimate tensile strength for elastomers

I'm doing experiments with an elastomer and I'd like to know how I should determine tensile strength in practice. Is this the point where I begin to observe tears in the elastomer or where the ...
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1answer
38 views

Understanding stress-strain calculations

I'm trying to compute the stress-strain curve for an elastic material with cylindrical geometry subject to an increasing uniaxial load. I understand that this requires: stress = $F/A_0$ where $A_0$, ...
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1answer
25 views

Does silicone rubber have a fundamental frequency?

I'm wondering whether impulse excitation techniques may be used to derive the Young's Modulus and Poisson Ratio of Silicone rubber.
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1answer
39 views

About elongation produced in a body, when 2 forces of equal magnitude but opp. in direction are applied on a body

When 2 oppositely- directed forces are applied on the same body , they act at the body's center of mass(com). The vector sum of the forces thus becomes 0(zero). How do the forces then bring about ...
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1answer
46 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 ...
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1answer
27 views

What is the short time limit of Maxwell viscoelastic fluids?

The Maxwell model for viscoelastic fluids writes: $$ \tau\stackrel{\triangledown}{\sigma}+\sigma=2\eta D(v) $$ where $D(v) = \frac{1}{2}(\nabla v +\nabla v^T)$, $v$ velocity and $\sigma$ stress tensor ...
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1answer
44 views

Origin of a unique stress-strain relation

In a paper by Kees Wapenaar titled, "Retrieving the Elastodynamic Green's Function of an Arbitrary Inhomogeneous Medium by Cross Correlation" (2004), the following is stated: "In the space-frequency ...
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1answer
117 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 ...
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2answers
91 views

Differences between elastic moduli

Is it true that in materials like aluminum and copper, the correct order of elastic moduli, in terms of value are: Bulk < Young's < shear modulii If this is correct, why is this the case?
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1answer
209 views

On what parameters is breaking stress dependent?

I have recently studied Elasticity in materials. There was a question about breaking stress that if the area along which a linear force is applied is doubled, then what happens to the breaking stress. ...
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1answer
43 views

Tensile stress, is the pressure given indicating just one side?

I'm studying elasticity right now in my chemistry class, and I'm confused as to what exactly tensile stress (and maybe compression stress too) might mean. It's given in N/m^2. And you're stretching ...
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1answer
1k views

Modulus of rigidity inside the water

Transverse wave can't travel inside the water. It travels in solid and on the surface of water because they have modulus of rigidity. What is modulus of rigidity? and why there is no modulus of ...
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1answer
156 views

Why don't we take into account the width contraction of the wire in calculating the stress strain relationship for a stretched wire?

In the stress-strain relationship for a stretched wire, we say that $\frac{F}{A}=Y\frac{β}{l}$; where β is the change in length and the rest have their usual meaning. We also say that there is a ...
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1answer
250 views

question about elasticity and tensile strength of wires

To the best of my knowledge, if you double the cross sectional area of a wire you double the maximum weight it can support before breaking. But what if you use two wires of the original cross ...
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1answer
780 views

effect of object mass in coeficient of restitution

I know the coefficient of restitution depends on the velocity before and after the impact of a bouncing ball. How does the mass affect it. Can't figure it out. v ...
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1answer
565 views

Confusion In solving a problem related to Elasticity?

This the question given in my textbook A thin, uniform rod of length $l$ is rotated with constant angular speed $\omega$ about an axis passing through it's one end and perpendicular to one end of ...
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1answer
858 views

Calculation of a bending moment

I'd like to calculate the bending moment of a cantilever, fixed at its base, and submitted to a certain stress on a specific spot, but I can't find the proper definition of this bending moment (first ...
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1answer
242 views

Simplifying some math for an ant-on-rubber-band problem

OK, I've been doing this problem for fun (it's a great problem, BTW!): http://www.physics.harvard.edu/academics/undergrad/probweek/prob76.pdf Here is the solution: http://www.physics.harvard.edu/...
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2answers
276 views

Stress and strain

Let us consider a rod having a young's modulus $Y$. Let it be of length $l$, and suppose it is suspended from a point P. Let us pull the rod with a force $F$ at a point Q which is at a distance $2/3l$ ...
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0answers
11 views

Interpretation of Evanescent Elastic Waves for Material Damage

In elastodynamic theory, when the slowness vector is imaginary, the resulting elastic waves are called evanescent. I have read that this corresponds to exponential decay. I have also read that complex ...
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2answers
28 views

Is it possible a linear compression to result in rotational movement? [on hold]

I am looking for a spring or elastic mechanism that I will compress linearly; and when I let it go, it will rotate. Is there such a mechanism or spring?
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2answers
34 views

Rubber on atomic scale during bending

When you compare rubber with steel whats the difference on the atomic scale when you bend it?
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14 views

relationship between creep and hysteresis

For a particular material that's suspected to be viscoelastic, I observe a hysteresis curve where the difference in elongation between the loading and unloading curves ranges between 5% and 10% for a ...