What is Elasticity: Definition and 203 Discussions

A good's price elasticity of demand is a measure of how sensitive the quantity demanded of it is to its price. When the price rises, quantity demanded falls for almost any good, but it falls more for some than for others. The price elasticity gives the percentage change in quantity demanded when there is a one percent increase in price, holding everything else constant. If the elasticity is -2, that means a one percent price rise leads to a two percent decline in quantity demanded. Other elasticities measure how the quantity demanded changes with other variables (e.g. the income elasticity of demand for consumer income changes).Price elasticities are negative except in special cases. If a good is said to have an elasticity of 2, it almost always means that the good has an elasticity of -2 according to the formal definition. The phrase "more elastic" means that a good's elasticity has greater magnitude, ignoring the sign. Only goods which do not conform to the law of demand, such as Veblen and Giffen goods, have a positive elasticity. Demand for a good is said to be inelastic when the elasticity is less than one in absolute value: that is, changes in price have a relatively small effect on the quantity demanded. Demand for a good is said to be elastic when the elasticity is greater than one. A good with an elasticity of -2 has elastic demand because quantity falls twice as much as the price increase; an elasticity of -0.5 indicates inelastic demand because the quantity response is half the price increase.Revenue is maximised when price is set so that the elasticity is exactly one. The good's elasticity can also be used to predict the incidence (or "burden") of a tax on that good. Various research methods are used to determine price elasticity, including test markets, analysis of historical sales data and conjoint analysis.
Price elasticity of demand further divided into:
Perfectly Elastic Demand (∞),
Perfectly Inelastic Demand ( 0 ),
Relatively Elastic Demand (> 1),
Relatively Inelastic Demand (< 1),
Unitary Elasticity Demand (= 1).

View More On Wikipedia.org
  1. S

    Bending strength of timber and modulus of elasticity.

    I am constructing a glutamine beam as part of a project and need to estimate the load at which the beam fails in bending and the load that will give deflection of length/200. I have been allowed to do a none destructive test on each piece of timber to be used in my beam. This has given me a...
  2. H

    How Do Mass and Young's Modulus Affect Cylinder Stability?

    Homework Statement two cylinders A and B with the same initial length, standing upright with one another. Then on top of the cylinder is placed a rod horizontally as shown. If the known diameter and Young's modulus cylinder A is twice the diameter and Young's modulus cylinder B. Determine: 1...
  3. N

    Clarification of the laws applied

    I am a first year student and i am required to build one thing based on one physics law . if i build a rubber band powered airplane , what laws should i say it applies? and what about rubber band powered car??
  4. M

    Exponential behavior in elasticity?

    Hi! I know some constitutive models for elastic materials like Neo-Hooke or Mooney-Rivlin, which give a relation between elongation ##\lambda=y/y_o## (where ##y## and ##y_o## are the length of the elastic material in a uniaxial compression test in the direction of the compression at stress ##P##...
  5. Chrono G. Xay

    Predicting Initial Length of String Needed Before Stretch

    I have put together an equation whose purpose is: With a desired 'magnitude of static friction' ( μ_s ), 'fundamental frequency' ( f ), and 'tension' ( T ), initial conditions such as 'string breakover angle' ( Θ_0 ), 'nut-tuner distance' ( L_{h,0} ), and 'string diameter' ( d ), and...
  6. Chrono G. Xay

    Tension (and Frequency) with Change in Temperature

    At one point I had been trying to construct an equation which would calculate the tension on a tuned string with a change in temperature (and therefore the fundamental frequency), but found my calculations were wrong. By extension, the purpose of the project was to be able to calculate what...
  7. A

    Calculate elasticity of rubber balloon

    Dear readers, For a Biomedical Engineering project I have to develop a model for the respiratory system of a neonate. This will be done by using pressure/volume data of the lungs. To model these, I would like to use a rubber balloon. However the calculation are more difficult than I thought...
  8. Tam Le

    Elasticity: Definition, Examples, & Illustrations

    I read somewhere that elasticity is the measure of the tendency of an object to resist deformation (similar to how inertia resists motion). I also read elsewhere that elasticity is the measure of how well an object returns to its shape/form after removing the applied force. Which...
  9. B

    Tensile Test Specimen Point of Failure

    I am a part C Mechanical Engineering student and have been undertaking a project investigating the strain sensitivity of a particular glass filled composite. From my quasi-static results, the stress-strain curves seem to be reasonable and match that of the mechanical material properties...
  10. xxyourstruly

    How do I calculate percent elasticity?

    Homework Statement I was given a chart to figure out the different momentum and kinetic energies of different collisions (elastic and inelastic) and in the lab he posed the question "Calculate the percent elasticity for each of the collisions." Homework Equations conservation of momentum...
  11. Dennydont

    What is the maximum load the concrete can support?

    Homework Statement A certain type of concrete has a tensile breaking stress of 3.1 MN/m^2, a compressive breaking stress of 37.7 MN/m^2 and a shear breaking stress of 9.4 MN/m^2. A circular pillar of this concrete has a radius of 0.6 m. What is the maximum load it can support assuming that it...
  12. E

    Searching for any lead on realistic cord mechanics

    Hi all, I'm a physicist, and I'm now trying to understand and model a problem with a multishafted cord, being pulled from one side in order to transfer force. The cord has its own elastic properties (elongation, bending etc.), it goes through several pulleys with friction, and most likely its...
  13. N

    Physics Report Help -- Simple Harmonic motion and Elastic force

    Homework Statement So I have to write a report based on an experiment that I have conducted. I know that my report is connected with Simple Harmonic motion and Elastic force, but I do not know how to describe it in a more efficient/scientific way. Essentially, I am dropping a weight (constant)...
  14. S

    Calculate elasticity of collision from kinetic energy loss?

    Homework Statement After a lot of searching I can't seem to find a way to solve this. Basically, for a bouncing ball, if I know the dropped height and rebound height in a vacuum. How do I calculate the elasticity between the ball and the floor? Homework Equations K = 1/2 mv2 The Attempt at a...
  15. R

    Anisotropic Modulus of elasticity and Poisson's ratio

    Hi, I have some experimental data and I am interested to use this data to calculated modulus of elasticiy (young's modulus) and Poisson's ratio. The material for which the data is given in an anisotropic material, therefore I need to calculate modulus of elasticity and poisson's ration is x,y...
  16. R

    Anisotropic Modulus of elasticity and Poisson's ratio

    Hi, I have some experimental data and I am interested to use this data to calculated modulus of elasticiy (young's modulus) and Poisson's ratio. The material for which the data is given in an anisotropic material, therefore I need to calculate modulus of elasticity and poisson's ration is x,y...
  17. J

    Closed Form Equations for Elasticity Properties for Anisotropic Materials

    Hi all, I'm wondering if anyone knows of a way to obtain elasticity properties (Ex, Ey, Ez, Gxy, Gxz, Gyz, vxy, vxz, vyz) from the terms of a 6x6 anisotropic stiffness or compliance matrix. I'm looking for a closed form solution, preferably. I would think that there should be a closed form...
  18. N

    Finding yield strength with modulus of elasticity

    Homework Statement Grade 1020 Steel has a yield strength of 42ksi and E modulus of 30 mpsi. Another grade of steel has yield strength 132 ksi. What is its E modulus? Homework Equations E=FL/EA This is the equation i should be using to find e modulus I thing The Attempt at a Solution I don't...
  19. PetePetePete

    Stress and Strain Coursework Question

    I am struggling with a question in my coursework, and would appreciate some guidance. The question is: The component shown in Fig 1 is made from a material with the following properties and is subjected to a compressive force of 5kN. Material Properties : Young’s Modulus of Elasticity – 200...
  20. C

    Elasticity theory, extracting the boundary conditions

    Homework Statement I am trying to extract the constant of integration after integrating the following stress equation (I got this by solving a system of ODEs for the upper and lower tablets (attached), quite tedious to paste it all here): σ = β * sinh(λx/2) * cosh( λ(L-x)/2 ) Where σ...
  21. Z

    Elasticity: Determine zero normal stress plane

    Given the stress tensor in a point, determine the zero normal stress plane. ...2 3 0 T= 3 2 0 ...0 0 5 ---------------------- Eigenvalues: σ1=σ2=5, σ3=-1 It must be simple, but I don't know how to determine the normal vector of that plane analytically. I know σ=0. t=Tn=σ+τ=τ If normal stress...
  22. M

    Microeconomics: Unitary elasticity properties

    Homework Statement The demand for good A is unit elastic. This means that a 5 percent increase in price will ______ A) result in an infinite increase in the quantity of A demanded. B) result in a 1 percent decrease in the quantity of A demanded. C) result in 5 percent increase in quantity...
  23. M

    Using price elasticity of demand to help determining a pricing policy?

    How can price elasticity of demand for some data help in determining a decision making process in a future pricing policy? I have some data that I want to analyze. I am given prices and demand for different products over a period of time. And I would like to use the price elasticity data to get...
  24. G

    Comparing Modulus of Elasticity in Maths vs Physics

    I'm learning about Hooke's law and modulus of elasticity (also known as youngs modulus) but it seems I am being taught it differently in maths and physics. In maths I am taught that T=λx/l and λ is the modulus of elasticity, measured in Newtons. In physics I am taught that T=λAx/l where λ is...
  25. Z

    Tax incidence and Price Elasticity

    Hello everyone, I see that economists define a formula to calculate how the tax is shared between consumers and suppliers. They call it "Pass-thorugh" fraction: Customers share = (-PED)/(PES-PED) Suppliers share = PES/(PES-PED) However I see this doesn't work when I use it with...
  26. D

    Solve Elasticity Problem: Young Modulus, Diameter 0.6mm

    Homework Statement In the fig AB is a wire of diameter 0.6mm and Young modulus of the material 2x10^11Nm^-2. C is the mid point of the wire. How much will the point B go down? Homework Equations Y=FL/Al where L= original length of the wire and l=extension in the wire The Attempt at...
  27. E

    Calculating Sales Change with Price Elasticity of Demand

    Homework Statement Given a price elasticity of 1.6 and an initial sales number of 10000 what would be the sales number if price went from 4.99 to 10.00? Homework Equations Price Elasticity of Demand = % Change in Quantity Demanded / % Change in Price The Attempt at a Solution...
  28. L

    Price Elasticity, Partial Derivative

    Hi all, I've got a question regarding a price elasticity problem and a partial derivative. That's what's given for the exercise: So, first of all we calculate all the demand with the given information. Which is: And then we come to the actual problem. (4. b) ) How do they...
  29. R

    Economics: Elasticity Differential Equation Question

    Hi. Let me preface this by saying that I know nothing about economics. However, I learned a little bit about the concept of price elasticity of demand (that for something really elastic, if price goes up a little, demand will go down a lot), and I came across an equation relating price, demand...
  30. P

    Modulus of Elasticity with shear Corrected

    I appreciate your help with this problem from a Three point Bending Test in Wood samples Homework Statement Force: 2400 N Deflection: 4.3 mm Span: 343 mm Length: 392 mm b: 24.01 mm d: 24.25 MOE: 16445.15 MPa How can I calculate the Modulus of Elasticity with shear corrected...
  31. C

    Understanding the Relationship Between Elasticity and Young's Modulus

    Homework Statement This is a rather conceptual question, but is there a difference between elasticity and young's modulus? I know that the young's modulus can also be stated as the modulus of elasticity, but is it incorrect to say that a substance with a higher young's modulus has a low...
  32. J

    Young's Modulus of Elasticity Problems -

    Young's Modulus of Elasticity Problems - URGENT Homework Statement Calculate Young's Modulus of Elasticity for the three materials using the graphs only. Stress (N/m2) Strain 70 0.06 100 0.11 150 0.22 200 0.35 220...
  33. MarkFL

    MHB MathRocks' question at Yahoo Answers regarding price elasticity of demand

    Here is the question: Here is a link to the question: Calc price elasticity problem and demand? - Yahoo! Answers I have posted a link there to this topic so the OP can find my response.
  34. J

    Finding Engineering Strain Just Before Yield for Wire w/ Modulus of Elasticity

    The engineering yield strength, the modulus of elasticity, the original diameter and final diameter of a wire are given. That wire is stretched and it diameter decreases. I am trying to find the engineering strain just before yield and the corresponding true strain. So I assume I will find...
  35. M

    Formula of modulus of elasticity?

    Homework Statement How to calculate the modulus of elasticity algebraically? Especially that of a pine wood rectangular cantilever beam? I have a few measurements here. The area inertia is .413 cm^4, the length of the unsupported part of the beam is at 40 centimeters(the whole beam is around 66...
  36. P

    Solving an Elasticity Problem - Any Help Appreciated!

    Hello, I am struggling with this problem. It is probably the easiest problem ever... What I did: The plane has 2 stress components. σn and σs. σn is a multiple of (l, m, k) vector. For σs, I made up a vector (a, b, c) which is orthogonal to (l, m, k). And I equated all vectors. I'm...
  37. V

    Mechanical principles - Stess and modulus of elasticity

    Mechanical principles - Stress and modulus of elasticity Homework Statement A 2.2m long steel towing bar of solid circular section diameter of 45mm is expected to carry a maximum load of 210 kN. The safety factor is 4; and for the steel the UTS is 540 MNm-2 and the modulus of elasticity is...
  38. M

    Elasticity (understanding elasticity from stress strain curve)

    Hello .. I have problem understanding how to decide which material is more elastic based on stress strain curve.. my understanding is as follows 1)if a material has big youngs modulus.. then it is more stiff 2)a material with a big youngs modulus may be or may not be very elastic (elasticity...
  39. I

    Discerning the Elasticity Modulus of Brittle Cast Iron from Test Data

    Here goes try number two, the forum deleted my last post. :cry: First time poster, so hopefully I'm following the rules, I do apologise if I'm not. I have a problem with my lab report, I would be very grateful if anyone could help. Thanks. Homework Statement I'm writing a tensile test lab...
  40. S

    Solid Elasticity, Steel Rod shortening

    Homework Statement We have a steel rod with density ρ = 7,90 kg/m^3. When it's horizontally on the floor, it's length is L = 6,00m. The rods surface area A is a circle with radius r=0,04m. Steel has Young modulus E=2,1 \cdot 10^{11} Now the rod is lifted up so it's vertically straight...
  41. M

    MHB Econ: Solving Elasticity Problem & Analyzing Revenue Function

    The demand function for a product is given by p = 800 -4x, 0 <= X <= 200, where p is the price (in dollars) and x is the number of units. (a) Determine when the demand is elastic, inelastic and of unit elasticity. (b) Use the result of part (a) to describe the behavior of the revenue...
  42. M

    MHB Find Price Elasticity of Demand

    Find price elasticity of demand for the demand function at the indicated x-value. Is the demand elastic, inelastic or of unit elasticity at the indicated x-value? Use a graphing utility to graph the revenue function, and identify the intervals of elasticity and inelasticity. ... I will list...
  43. K

    Trouble with algebra at the end of an elasticity problem

    I have a spherical shell with inner radius a_{1} and outer radius a_{2} I have worked out that the tension at r=a_{1} is \tau=\frac{2a_{1}^3+a_{2}^3}{2(a_{2}^{3}-a_{1}^{3})}P_{1} (P_{1} is pressure from the inside of the shell, causing the tension. Now if the shell is not very thick...
  44. T

    Using Stress/Strain Curve to Find Yield Strength and Modulus of Elasticity

    Hey guys, I recently did a compression lab with different materials (wood and pvc pipe) and I have to plot the stress/strain curves given the data collected, as well as find yield strength (0.2% offset), ultimate compressive strength, and modulus of elasticity. I've already calculated...
  45. K

    Trouble with simple elasticity derivation

    Deriving the basics of infinitesmal elasticity, I have a proof regarding the physical significance of the strain tensor E_{11} So we are considering a material line element parallel with the x_{1} axis being deformed. At a point in the proof we have du_{1} = u_{1}(x_{1}+dL_{0}, x_{2}...
  46. V

    I have a basic doubt in the theory of stress and elasticity. Please help me

    A Book says, " When a load is acting on a member, it undergoes deformation. An internal resistance is developed against deformation by the member and the intensity of this internal resistance is called stress." I also read, "When a member is in its elastic range, it offers resistance against...
  47. K

    Why study 'Theory of Elasticity'

    Hi. What is the point of studying Advanced Elasticity course apart from strength of materials/solid mechanics?? One of my friend says that there's no need to study this as the content of this course is rarely used in industrial practice. He says that the (Stress Analysis) Engineers merely use...
  48. M

    Elasticity, free energy of isotropic body mismatch

    I'm looking at the free energy of a body (theory of elasticity) but I can't really square the general expression with the one usually used for isotropic bodies. According to wikipedia (http://en.wikipedia.org/wiki/Elastic_energy), Landau & Lifgarbagez etc the general expression for the free...
  49. C

    Economics: Elasticity of substitution between capital and labor

    Homework Statement Am I right or wrong on the following? The more capital is needed to replace one unit of labor to attain the same production level, the lower the elasticity of substitution between capital and labor. It can measure how productive the capital in question is, and/or how...
  50. T

    Determine the modulus of elasticity, Poisson's ratio and the shear modulus.

    Homework Statement A rod with a diameter of 1.00 in and length of 6.0 ft undergoes an axial deformation of 0.150 in when subjected to an axial force of 52.0 kip. The diameter of the rod decreases by 0.0007 in at this load. Determine the modulus of elasticity, Poisson's ratio and the shear...
Back
Top