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. R

    Elasticity and Young's Modulus

    Homework Statement Consider a metal bar of length L, cross-sectional area A, equilibrium atomic separation x, and Young's modulus E. When a tension force F is applied to the bar, it causes an extension ΔL. Calculate the atomic force constant k by deriving expressions for (a) the number of...
  2. M

    Few Problems (Waves, Elasticity, SHM)

    1. Homework Statement : Hello PF! Here are a few problems I'm stuck on. 1. When a tuning fork and a source of frequency 200 Hz are sounded together, 4 beats/sec are heard. When the tuning fork is loaded with some wax, again 4 beats/sec are heard. Then the original frequency of the fork was...
  3. A

    Aluminum 6061 Modulus of Elasticity

    Bare with me as I'm brand new to all of this, and my inexperience may show, but i have what may be a simple question to some of you. I'm conducting a lab experiment in my Materials lab I will be testing the the strength of 3 different Aluminum 6061 specimens. I have an L beam, thin walled...
  4. F

    What is finite elasticity talking about?

    Hi, dear all, recently study the solid mechanic continuity, keep reading about to solve large deformation of material, you will need so called "finite elasticity" What is this finite elasticity refer to ? "Finite elasticity is a theory of elastic materials capable of undergoing large...
  5. M

    Modulus of elasticity, problem. Graph and table.

    Attached is the graph and small part of table that i have chosen from the elastic range (first column extension, second column load) from a tensile test. I am trying to calculate youngs modulus of elasticity but can't seem to get a figure close to that of the common figure for the material...
  6. Ivan Seeking

    Yield vs elasticity in aluminum

    I have an application that involves forming 2024 aluminum in the T42 state. I need to determine [approximate] the amount of elastic stretch vs yield once the yield point has been exceeded. In other words, once beyond the yield point, how much of the strain results in addional yield, as opposed...
  7. E

    Torque Equilibrium and Elasticity problem

    Homework Statement A 300 kg nonuniform boom, 6.0 m long, is loosely pinned at the pivot at P. A 1000 kg block is suspended from the end of the boom at A. The boom forms a 30° angle with the horizontal, and is supported by a cable, 4.0 m long, between points D and B. Point B is 4.0 m from P...
  8. B

    MHB Calculating elasticity of substitution help

    Calculate the elasticity of substitution between y and x for F(x,y) = 10x^2 + 15y^2 I was able to calculate the Marginal Rate of Substitution as 20x/30y but I'm not sure how to proceed past that. The answer in the book is -1. Any and all help appreciated!
  9. M

    Questions about harmonic analysis as applied to elasticity

    Hello everyone, I am trying to use a combination of a couple different types of harmonic potential formulations (attached - see question 2) to arrive at an analytic solution to a 3D linear elasticity problem. The problem involves a finite simply connected solid of revolution with mixed...
  10. V

    Solving Momentum and Elasticity Problem

    Hello form, Vaironl here. I have some few very basic questions. Why might you ask? I came from a trip about a week ago and in my physics class we are discussing momentum, and elasticity. I asked my teacher for help but he really is a bit busy at the moment, and the semester/quarter will soon...
  11. A

    Physics books for (elasticity - hydraustatics)

    HEllo Can I find a physics reference for these three topics ?? I have Serway but it just mentions elasticity in a short form which is not so good and has no thing about surfacetention - bubbles , what book could have theese topics in an extended form , Just as serway explains motion and...
  12. M

    Explore Elasticity: Is There a Constant Relation Between Elasticity & Density?

    http://www.physicsclassroom.com/Class/sound/u11l2c.cfm according to this,rubber is not elastic The problem is that I read before that elasticity is the physical property of the material when it deforms under stress(eg external forces),but it returns to its shape when the stress is removed. An...
  13. V

    Help with Homework Statement 1b: Elasticity & Pressure

    I need help on question 1b here, Homework Statement 1. In a one-minute interval, 1000 hailstones, each of mass 0.5 g and speed 10ms-1, strike a window pane of area 1m2 at an angle of 45°. (a) If the collisions are elastic, calculate : (i) the average force and (ii) the average...
  14. D

    Exploring Spacetime Elasticity & Mass Research

    I am curious if there has been any research into the elasticity of spacetime in regards to mass. If we consider that a fabric is resistive to a degree to an object it could be said that an object must poses a certain amount of mass before it can cause a divet in spacetime.
  15. M

    If ultrasound can be used to measure elasticity

    can you simply extract the elasticity from ultrasound medical images? I don't know ultrasound very much but I just found out it can measure elasticity. under what condition can ultrasound be used to measure elasticity of some deformable object and do ultrasound medical images qualified for...
  16. U

    Calculating the Elasticity of an Annular Disc Without Prior Information

    Hi, I have an annular disc that looks like the following: I need to get the elasticity of the material, since I don't have any information on it. Does anyone have any suggestions on how I can calculate the elasticity? Maybe I can get a force/displacement curve by bending the disc...
  17. P

    How Many Steel Strands Are Needed to Safely Lower a Lift into a Mine?

    A lift is used to lower miners 4000m into a mine. The lift is supported by many high strength steel strands of 3mm diameter each. The ultimate stress for the steel strands is 1200MPa and the allowable stress is 600MPa. The empty lift weighs 15kN. It has a capacity of 20 persons. The density of...
  18. O

    L&L - Elasticity - couple questions on notation

    Edit - maybe I have the notaton figured out now and am just confused. Homework Statement The below relevant quotations come from Landau and Lifgarbagez, volume 7 : The theory of elasticity, chapter 1. 2. Relevant quotations Page 2: where uik is the strain tensor, dl is the original...
  19. N

    Exploring the Effects of Space-Time Fabric Elasticity on Time Flow

    if i consider space time to b a fabric as considered by einstein then expansion of this fabric leads in two direction 1-if the fabric has high elasticity then the curvature of space caused by the a massive object will keep on increasing,thus the flow of time will be faster...
  20. J

    Price Elasticity of Demand Help

    q= (39/3.6)^2/3 p=(39/(3.6^3/2) Find price elasticity of demand when p=$3.6. I already substituted the 3.6 in there. I keep getting 1.5 but its saying it wrong please solve and help.
  21. A

    Equilibrium and Elasticity problems

    Hello, Please I have 3 questions and I don't know how to solve them. So, please help me with the way to solve these questions. Q1 : A uniform 267-g meter stick can be balanced by a 217-g weight placed at the 100-cm mark if the fulcrum is placed at the point marked: Give your answer...
  22. T

    Calculating modulus of elasticity?

    I'm trying to figure out how to calculate the modulus of elasticity for a board clamped to a surface plate at one end and free-floating on the other. I've measured the deflection with a 1k weight at the free end of the board. So I've got that data as well as the dimensions of the free-hanging...
  23. K

    Deflection and Modulus of Elasticity

    Homework Statement Calculate the deflection at the end of a rod whose dimensions are 1m x 0.1m x 0.1m, when a load of 100N is applied. The modulus of elasticity is given as 1 x 1011 (N/m2) Homework Equations d = PL/AE where d = end deflection of bar in metres (in m) P = the applied...
  24. A

    Conceptual question on Modulus of elasticity

    Homework Statement Lets say a wire has Youngs modulus Y, Initial length L area A and is supporting some external load/force of magnitude F...its extension is dl..We say that the Potential energy of wire is 1/2(YA/L)(dl2)...But i am having a problen with the energy changes... Homework...
  25. N

    Oscillations, velocity, elasticity

    Homework Statement A 0.2 kg object, suspended from a spring with a spring constant of k = 10 N/m, is moving in simple harmonic motion and has an amplitude of 0.08 m. What is its velocity at the instant when its displacement is 0.04 m? Homework Equations v=root(F/m/l) The Attempt...
  26. N

    Understanding Oscillation Frequencies and Mass Ratios in Elastic Systems

    Homework Statement Ok. here's the deal. since i have started physics, i have been having problems with this concept. when you have an equation that has two sides to it, such as sqroot(F/m/l)=freq(wavelength) and they adjuct one side, how do you know what to do the other side? For...
  27. P

    Solving Elasticity & Work Problems

    Homework Statement A wire of length L, Young's modulus Y, and cross sectional area A, is stretch elastically by an amount ∆L. show that the work done in stretching a wire must be W = [YA(∆L)^2] / 2L Homework Equations ∆L = (1/Y)(F/A)L W = F * d (where displacement = ∆L) The...
  28. P

    Finding Elasticity in Demand: Solving for p in the Demand Equation

    Homework Statement Derivatives and elasticity: The demand equation for a product is q = \left(\frac{20-p}{2}\right)^{2} for 0 \leq p \leq 20. a) find all values of p for which demand is elastic. Homework Equations Elasticity: \eta = \frac{p}{q} x \frac{dq}{dp} The Attempt at a...
  29. D

    Velocity after collision (elasticity)

    This is a two part problem, but once I figure out one part I can do the other. Homework Statement a) A(n) 67.5 g object moving to the right at 26.7 cm/s overtakes and collides elastically with a(n) 18.8 g object moving in the same direction at 17.952 cm/s. Find the velocity of the first...
  30. mrspeedybob

    Do materials have temporal elasticity?

    If I take a spring and move one end at a different velocity then the other tension will build in the spring and when released it will return to its natural shape. What If I take an object and put one end at the edge of a centrifuge and the other at the center. Acceleration and velocity will...
  31. D

    Calculation on Price Elasticity of Demand problem Need Advices .

    Calculation on Price Elasticity of Demand problem ... Need Advices ... Give following demand function: Q = 2.0 P^-1.33Y^2.0A^0.50 Q = Quantity demanded (Thousads of units) P = Prices ($/Unit) Y = Disposable income per capita ($ thousands) A = Advertising expenditures ($ thousands)...
  32. A

    Boussinesq Elasticity Problem Derivation

    Where can I find the derivation of the Boussinesq problem of elasticity (point load on an isotropic elastic infinite half-plane)? Besides the original 19th century paper, of course. Thanks!
  33. H

    Nonlinear Elasticity: Calculating Internal Forces

    High I am working on the geometrically nonlinear finite element method. I now that in this method, the internal forces on each node must be equal to external forces. How can I calculate internal forces?
  34. G

    Momentum and elasticity and this astronaut dude

    In my physics class (School's over now, so I can't ask my teacher.) we had this interesting problem for our final. (No, this isn't homework) We didn't do elasticity, soo... I dunno. An astronaut (It's in space to eliminate air resistance and gravity- it IS high school physics :tongue:) has a...
  35. D

    On Physical Lines of Force: elasticity, density and the speed of light

    Maxwell: -"The ratio of m to mu varies in different substances; but in a medium whose elasticity depend entirely upon forces acting between pairs of particles, this ratio is that of 6 to 5, and in this case E^2= Pi*m" Q1: What is this 6:5 ratio and how did he make that conclusion? Q2: What...
  36. A

    Pitch of sound: Elasticity vs Tension of string

    Hi there, I saw this question in a book. Basically, we are asked to comment on the effects of Tension of a guitar chord and the Elasticity of the chord itself on the frequency of the sound the guitar produces. I understand Elasticity will have a positive effect on the speed of sound, and...
  37. W

    Calculating the Modulus of Elasticity: A Guide

    After making a chart in Excel and obtaining the equation " Y= 3E+07x+2445.3 " Now i need to calculate the modulus of elasticity. I know that the slope of the equation gives the modulus of elasticity. but I have no clue how to even begin solving the equation Y= 3E+07x+2445.3I do know...
  38. A

    Which types of elasticity are involved?

    Homework Statement A pole projects horizontally from the front wall of a shop. A 6.1-kg sign hangs from the pole at a point 2.2 m from the wall. (a) What is the torque due to this sign calculated about the print where the pole meets the wall? (b) If the pole is not to fall off, there...
  39. I

    Static equilibirum, elasticity, fracture problem

    1. A 19.0 kg ball is supported from the ceiling by rope A. Rope B pulls downward and to the side on the ball. If the angle of A to the vertical is 22 degrees and if B makes an angle of 53 degrees to the vertical find the tension in rope A and then find the tension in rope B
  40. I

    Using calculus to prove a relation between demand elasticity and AR, MR

    Hi all, The problem asks to prove: e_{Q,P} = \frac{AR}{AR-MR} In which AR is average revenue and MR is marginal revenue. Then verify this for demand equation p = a-bx I developed several steps: \begin{flalign*}AR = \frac{TR(Q)}{Q} ; MR = \frac{dTR(Q)}{dQ} \\* \frac{AR}{AR-MR}...
  41. L

    How Do You Calculate the Modulus of Elasticity from Load and Extension Data?

    new to physics can some one please help me with b and c Load (kN) 0 20 30 50 60 73 90 94 Extension (mm) 0 0.150 0.225 0.375 0.453 0.550 0.900 1.100 a) Draw a graph with load on the y-axis and extension on the x-axis...
  42. R

    Concept of Elasticity on an atomic level

    Hi guys, Can someone explain The concept of ELASTICITY on an atomic level. To be clear can somebody please try and elaborate on how does a metal rod or bar or wire start to extend under the influence of an external load. What exactly happens on the interatomic level, say we...
  43. I

    Diesel - bulk modulus of elasticity

    Hi, I need the compressibility of diesel, depending on density, pressure(0-200bar) and temperatur. Do you know where to find these values? Thanks Inkog
  44. T

    Solving and Elasticity Problem: Differential Equation

    Homework Statement Show that the general solutions to the equations: (\frac{d^2}{dr^2}+\frac{1}{r})(\frac{d^2f_1}{dr^2} + \frac{1}{r}\frac{df_1}{dr}) = 0 (\frac{d^2}{dr^2}+\frac{1}{r}\frac{d}{dr} -\frac{4}{r^2})(\frac{d^2f_2}{dr^2}+\frac{1}{r}\frac{df_2}{dr}-\frac{4f_2}{r^2})=0 are...
  45. D

    Microeconomics questions (elasticity)

    When the price of popsicles rose from $10 to $11, consumer expenditures on them dropped by 10%, indicating that: A. Demand for popsicles had a price elasticity of -1 B. Demand for popsicles was price-elastic C. Popsicles are a normal good D. Popsicles are an inferior good E. More than one...
  46. D

    Microeconomics questions (elasticity)

    1.When the price of popsicles rose from $10 to $11, consumer expenditures on them dropped by 10%, indicating that: A. Demand for popsicles had a price elasticity of -1 B. Demand for popsicles was price-elastic C. Popsicles are a normal good D. Popsicles are an inferior good E. More than one...
  47. B

    How Can You Calculate the Elasticity of a Diving Board?

    Trying to find please equation(s) to calculate the "elasticity", "stiffness" of a homotropic cantilever diving board. Am seeking some analogue of the spring constant of Hooke's law, F= -kx, for this 3-D system. I'm unclear about whether Young's modulus applies here given the force ( or pressure...
  48. B

    Calculating Modulus of Elasticity for Material and Failure Point

    Hello, having some problems with calculating young's modulus, please help. [b]1. A Strain gauge records the following strain when a block of material is pulled: Force(N) Strain(%) 100 0.01 1000 0.1 2000 0.179 3100 0.9 Area of block =...
  49. C

    Simple Harmonic Motion and Elasticity

    Homework Statement A 0.01 kg bullet is fired horizontally into a 2.50 kg wooden block attached to one end of a massless, horizontal spring (spring constant = 845 N/m). The other end of the spring is fixed in place, and the spring is unstrained initially. The block rests on a horizontal...
  50. J

    Was the collision elastic or not?

    Homework Statement a billiard ball of mass of 0.115kg moves with a velocity of 12.5m/s toward a stationary billiard ball of identical mass and strikes it in a head on collision. the first billiard ball comes to a complete stop. determine whether the collision was elastic. Homework...
Back
Top