The tag has no wiki summary.

learn more… | top users | synonyms

0
votes
0answers
13 views

Elasticity of a body on which variable force is applied

Let us consider a rod of some cross sectional area A and length l.At one end a longitudinal foce of 5x acts on the rod. At a distance of l/2 from that point longitudinal force of 5x acts on the rod ...
0
votes
1answer
37 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 ...
3
votes
1answer
78 views

Reference Request: Fluid dynamics/Elasticity via Lagrangians

Would there be a book that does what Landau does in Fluid Mechanics and Theory of Elasticity using Lagrangian's/Action-principles, analogous to the presentation in Landau's mechanics? I have only ...
-1
votes
0answers
15 views

How to relate the height from which a object can fall with the young modulus of that object? [closed]

How to relate the height from which a object can fall without breaking with the Young modulus of that object?
0
votes
1answer
102 views

Degree of anisotropy of crystal tensors

Does there exist a scalar that can describe how anisotropic the elasticity of a crystal is? What about other tensors such as the permittivity or susceptibility? I found a Wikipedia article that was ...
2
votes
3answers
3k views

Why does rubber ball bounce back while iron ball doesn't?

Suppose there are two balls, one of rubber and the other metallic. There are of the same mass and are thrown on a wall with the same velocity. Why does a rubber ball bounce back while a metallic ball ...
-1
votes
1answer
60 views

Prove Poisson's Ratio is 0.5 [closed]

Poisson's ratio is the negative ratio of the transverse strain (_T) to the axial strain (_A). For an incompressible (density doesn't change), homogeneous (everything is the same molecule), ...
0
votes
0answers
14 views

Will a sodium bell ring clearly after being submerged in liquid nitrogen?

Lead is fairly soft at room temperature but rings clearly when cooled to liquid nitrogen temperatures. Sodium is even softer. If cooled to liquid nitrogen temperature, could it also ring?
1
vote
1answer
49 views

Confusion in Euler-Bernoulli beam theory

Euler-Bernoulli beam equation is given by $$ EI \frac{\mathrm d^2 u}{\mathrm d x^2} = M'(x) \\ EI \frac{\mathrm d u}{\mathrm d x} = xM'(x) + C_1 $$ Where, $E$ is modulus, $I$ is second moment of ...
2
votes
1answer
69 views

A question regarding collisions

Let us consider a system of 2 identical spherical bodies connected by a massless string that is taut. If one body is placed at the origin then the other is placed at some coordinate $(x,y)$. The ...
0
votes
1answer
28 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 ...
2
votes
0answers
11 views

Main differences between elastodynamic and light scattering when using S-matrix to find bound states

What are the main differences (top 5 if question is too broad), for using the S-matrix to find bound states, between elastodynamic and light scattering? (if it facilitates a higher quality ...
0
votes
1answer
28 views

Determining flexural modulus by performing 3 point bending test using hollow cylindrical tube

I would like to decide the flexural modulus of the material of plastic tube by performing 3 point bending test according to the ASTM D 790 procedure. In ASTM D 790, the form of the specimen is ...
0
votes
0answers
19 views

Role of the crystallographic point group on properties of tensorial elasticity

If a space point group for a crystal is known, does this automatically define the elastic tensor symmetry of the material? What further implications can be found? The crystallographic subgroups: ...
2
votes
1answer
421 views

Boundary conditions of Navier-Cauchy equation

I'm having difficulties with Neumann boundary conditions in Navier-Cauchy equations (a.k.a. the elastostatic equations). The trouble is that if I rotate a body then Neumann boundary condition should ...
0
votes
0answers
17 views

How to calculate a Mooney-Rivlin material

Well, I'm working on a fsi (fluid-solid/structure interaction) model. I've got ready the fluid part, now I need to get ready the solid part. Since I'm working with tissues, I need to use an ...
5
votes
0answers
91 views

Tensorial version of Hooke's law

It is well known that $${\boldsymbol F} = k {\boldsymbol x}$$ for isotropic media. Also, according to Wikipedia $$F_k = k_{jk} x_j$$ for some elastic tensor $k_{jk}$. I'm a bit confused as to how ...
1
vote
0answers
40 views

Physics of Wrinkling: Understanding inextensibility condition

I'm reading this very cool paper on the formation of wrinkles in elastic materials. The key result of the paper is a set of scaling laws for the amplitude and wavelength of wrinkles based on the ...
1
vote
1answer
23 views

Is shear modulus only applicable to cubical solids?

Do we have any real life/theoretical examples where shear modulus is applicable to non-cubical shapes?
1
vote
0answers
27 views

Example of materials with 21 independant coefficients in linear elasticity?

By definition of linear elasticity, the strain et stress tensors are related: \begin{equation} \boldsymbol{\sigma}=\mathbf{C}:\boldsymbol{\varepsilon} \end{equation} and because of minor and major ...
5
votes
2answers
1k views

Elasticity of Space; How does the expansion of Space affect gravity?

Does space have an elastic quality? What I was thinking about was if space is expanding, is it being 'stretched', like a balloon being blown up, and if so, is this causing gravity to weaken? Imagine ...
0
votes
1answer
36 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 ...
1
vote
0answers
55 views

Energy of a system

I'm considering a ring of mass $m$ sliding along a cardioid with equation $r=a(1+\cos\theta)$. We let the angle between the downward vertical and the radius vector be $\theta$. The ring is attached to ...
0
votes
3answers
53 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 ...
0
votes
1answer
52 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 ...
1
vote
1answer
54 views

Where does elastic energy come from?

I vaguely remember reading that the elastic potential energy of a spring, $\frac{1}{2} k x^2$ comes from mass which is turned into energy according to the law $E=mc^2$. I also remember hearing that ...
0
votes
2answers
70 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 ...
0
votes
1answer
41 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 ...
0
votes
0answers
43 views

Young elasticity modulus anisotropic media

Im studying anisotropic system composed by a elastic matrix (Young modulus $E_m$) filled with oriented rods. Given this filler orientation, the material is elastic-anisotropic, with Young elastic ...
1
vote
0answers
70 views

Double dot product in Cylindrical polar coordinates - Strain Energy

I'm working with a problem in linear elasticity, and I have to calculate the strain energy function as follows: $$2W=σ_{ij}ε_{ij}$$ Where σ and ε are symmetric rank 2 tensors. For cartesian ...
70
votes
12answers
9k views

Why is filling a balloon from your mouth much harder initially?

Why is it that when you first fill up a balloon, it's hard to get air through, but after inflating it a bit, it becomes much easier to further inflate the balloon?
1
vote
1answer
39 views

Deformation of the cylinder

There is given a cylinder with fixed side surface. On one base is being rendered constant pressure $p$, so cylinder cambers I'm trying to calculate the form of cambering. The problem is that height ...
1
vote
1answer
94 views

How does a fabric containing 10% stretch material make it stretchy?

Why should adding a small amount of a stretchy material make an otherwise non-stretchy fabric stretch? Shouldn't the non-stretch fibres still constrain the maximum stretch of the fabric?
8
votes
4answers
467 views

Is an entropic force an actual force that can be explained as a fundamental interaction?

Fundamental interactions, such as electromagnetism, the strong force, the weak force, and possibly gravitation, all have something in common: They can be described in terms of relativistic quantum ...
0
votes
1answer
51 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 ...
1
vote
0answers
246 views

What is the relationship between Elasticity and Compliance?

Compliance is like elasticity of hollow tube. Elasticity is less for instance for arteries so they are less compliant. There seems to some sort of relationship between compliance and elasticity. ...
1
vote
0answers
49 views

Finding Tension in an Elastic String?

I know that this is a homework type question and I'm not asking a particular physics question, but I'm really desperate for help. Here's the question: I tried to divide the string to 2 parts with ...
1
vote
1answer
70 views

Range of poissons ratio

I know the range of poisson's ratio is -1 to 0.5 but how do you arrive at this expression? I am a 11th grade student and I am not too familiar with advanced physics
-1
votes
2answers
266 views

Rubber bands and Hooke's law [closed]

Why does increasing the width of a rubber band increase its elastic constant($k$)? And why are the two variables directly proportional? Explain it in terms of the structure of the band, if that is ...
5
votes
1answer
246 views

Elastic band around a cylinder

An elastic band is stretched using a known force and then placed around a cylinder. How are the forces or tensions distributed? I assume there will be two components: firstly, a tangential or ...
0
votes
2answers
109 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 ...
6
votes
4answers
347 views

Aren't all collisions elastic at some level?

The more I think about it, inelastic collisions produce heat and sound which imply motion at some scale, right? Are inelastic collisions macroscopic events that ignore motion at microscopic levels? ...
2
votes
1answer
111 views

Calculating elastic energy constant [closed]

I ran into a kinetic physics problem: "A spring is hanging on the ceiling. Let's place an object 'M' at the end of the spring. Yet hold 'M' so the spring doesn't stretch. The distance between the ...
1
vote
0answers
101 views

Entropic force in polymers

According to my textbook, the elastic force in a rubber is caused to the tendency of the polymers to return to their initial disordered state of higher entropy. But isn't this looking at entropy on ...
1
vote
1answer
105 views

Coordinate-free derivation of the Lamé-Navier's elasticity equations

Linear static elasticity provides a local equation $-\mathrm{div}\sigma=f$, the constitutive law $\sigma=2\mu\epsilon+\lambda \mathrm{tr}(\epsilon)I$ as well as the strain-displacement relationship ...
0
votes
1answer
241 views

Maximum Weight Sustained by wire / Breaking limit of wire [closed]

I know that breaking stress depends on material of wire, not on the diameter or the length of wire. and also that Breaking load depends on the area of cross section of wire. But still i have a ...
2
votes
1answer
131 views

Meaning of Lagrange Multiplier in Ou-Yang and Helfrich's Shape equation for Membrane

Dear people in Physics Stackexchange, My question is mostly related to the following papers: U. Seifert, Z. Phys. B 97, 299 (1995). "The concept of effective tension for fluctuating vesicles". U. ...
0
votes
0answers
219 views

Caculating thermal stresses in a composite rod

The Question Between two rigid walls separated by a distance $l_1+l_2$, two rods of equal cross-section area $A$, and length, coefficient of linear expansion and Young's modulus $l_1, ...
0
votes
2answers
499 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 ...