What is Solid: Definition and 1000 Discussions

In object-oriented computer programming, SOLID is a mnemonic acronym for five design principles intended to make software designs more understandable, flexible, and maintainable. The principles are a subset of many principles promoted by American software engineer and instructor Robert C. Martin, first introduced in his 2000 paper Design Principles and Design Patterns.The SOLID concepts are

The Single-responsibility principle: "There should never be more than one reason for a class to change." In other words, every class should have only one responsibility.
The Open–closed principle: "Software entities ... should be open for extension, but closed for modification."
The Liskov substitution principle: "Functions that use pointers or references to base classes must be able to use objects of derived classes without knowing it". See also design by contract.
The Interface segregation principle: "Many client-specific interfaces are better than one general-purpose interface."
The Dependency inversion principle: "Depend upon abstractions, [not] concretions."The SOLID acronym was introduced later, around 2004, by Michael Feathers.Although the SOLID principles apply to any object-oriented design, they can also form a core philosophy for methodologies such as agile development or adaptive software development.

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  1. elisagroup

    Capacitance of an isolated sphere - solid vs hollow

    Seems the physics books agree that there is no difference in capacitance whether an isolated sphere is solid or hollow. And the reason mentioned for that always sounds something like the following: "The reason that the capacitance C, and hence the charge Q, is not affected by whether or not the...
  2. dRic2

    Solid State Book for graduate solid state physics

    Hi, I have to study for a solid state physics course and I'm not sure what textbook would be the best. Our professor suggested "Principles of the theory of Solids" by Ziman, or "Solid state physics" by Ashcroft. I'll intend to use both: one I buy, the other one I borrow from the library. But...
  3. L

    I Can you tell which solid a substance is by analyzing the phonons only?

    Can you tell what kind of solids by simply having access to the phonons only? Supposed you join a challenge where you will use any tools just to analyze the phonons (without telling you what kinds of solids). Can you tell what solids is it? Is there any geometric relationship between the...
  4. Philip Koeck

    Change in Entropy of a Solid or Liquid

    What about if we allow for a temperature and volume change in a solid or a liquid? Would the entropy change still only depend on the temperature change or also on the volume change. For a solid I would think that the volume change doesn't matter since it doesn't change the "amount of disorder"...
  5. Lone Wolf

    Resultant torque of a solid object

    a) ΔK = 1064 = 1/2 * I * (ω²(3) - ω²(2)) I = 2*1064/(ω²(3) - ω²(2)) If I assume α = n*t²: α = dω/dt --> ω = ∫ n* t² dt = n*t³/3 + ω0 = n*t³/3 ω(5) = 100 = n*5³/3 --> n = 2.4 α = 2.4 t² and ω = 2.4 * t³/3 ω(3) = 21.6 rad/s and ω(2) = 6.4 rad/s. Replacing the values: I = 2*1064/(21.6²-6.4²)...
  6. H

    Solid state electronics textbooks

    Summary: Please does anyone has a lecture note dat explain solid state electronic I need a lecture note or a textbook dat explain solid state electronic especially band gap Crystal growth Diffusion of semiconductor Fermini level
  7. A

    Relationship between k and orbital phase of solid state?

    I understand that quantum objects have wave and particle properties. I know that k = 2π / lamda. I am simply not understanding the x-axis of a bandstructure plot of E(k) vs. k. I've read parts of a book by Roald Hoffman on this subject. In the book it is shown that there are infinite chain of...
  8. P

    I If I had a cubic metre of solid osmium, a perfect cube....

    If i shon a red laser across the surface of the osmium cube 5mm above the solid perfect 1000mm cube, by how many degrees would it be deflected?
  9. L

    Pressures distribution: solid sphere on a flat surface

    In a real case (not ideally rigid bodies), a (e. g.) hard metal sphere is on a flat (e. g.) hard metal surface (a table) and the sphere is "charged" vertically on the table by a vertical force directed downward. In this situation, an engineer told me that the maximum pressure on the table is not...
  10. M

    Stepper torque calculation to drive a solid cylinder

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  11. taalf

    Formula for fictitious moments

    Hi All, Everyone knows so called "fictitious" forces, also known as "inertial" forces. They are forces felt by some mass point placed in a non-inertial frame. For example: a ball in a moving car or in a carousel. Maybe most intuitive fictitious forces are centrifugal forces, but there are also...
  12. Z

    Schools What are some good solid state theory masters schools in Europe?

    What are some good solid state/condensed matter theory schools in Europe ?
  13. arupel

    B Why is it possible to push your finger through butter?

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  14. Philip Koeck

    The average potential inside an electrically neutral solid

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  15. W

    MHB Volume of Solid Revolving Region About Line: 32pi/5

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  16. chemisthypnos

    Is neodymium powder as strong of a magnet as solid neodymium

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  17. brotherbobby

    Rotation of a Solid Cylinder

    Problem : A cylinder of mass ##M## and radius ##R## rotates with an angular velocity ##\omega_1## about an axis passing through its centre of symmetry. Two small masses each of mass ##m## (small in comparison to the radius of the cylinder) are glued to either of the two circular faces of the...
  18. Alexanddros81

    A jet comes in for a landing on solid ground

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  19. A

    What is the role of vibrational energy in heat conduction in solids?

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  20. hnnhcmmngs

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  21. S

    B Solid angle by placing one disk on a cylinder

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  22. Philip Koeck

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  23. confusedius

    Solid State Physics: Draw the Dispersion Relation from the Fermi Surface

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  24. Z

    "The theoritical minimum" modern equivalent for solid state?

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  25. gibberingmouther

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  26. J

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  27. K

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  28. G

    MHB Finding a particular angle withion Johnson Solid J2

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  29. P

    Is Xenon Considered a Crystalline Solid?

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  30. DracoMalfoy

    Thermal physics phase change: Liquid copper to solid

    Homework Statement How much energy must be removed from the system to turn liquid copper of mass 1.5kg at 1083 degrees celsius to solid copper at 1000 degrees celsius? a. -2.49X10^5J b. -3.67X10^4J c. 2.25X10^3J d. 9.45X10^4J e. -2.78X10^3J Homework Equations Q=Mc(Tf-Ti)...
  31. Dorian

    Solid Disk Pulley + 2 Mass system, v derivation using 2 methods

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  32. J

    Solid sphere rolling along a track

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  33. P

    I Chemical potential on a solid and its vapor pressure

    I have been reading the book "Nanostructures and Nanomaterials" by G. Cao and Y. Yang, and was intrigued by the following passage in page 33: "Assuming the vapor of solid phase obeys the ideal gas law, for the flat surface one can easily arrive at: μv − μ∞ = −kTlnP∞, where μv is the chemical...
  34. Eagle9

    I Can a liquid or solid plasma exist?

    Excuse me if this is naive question :oldsmile: Plasma is gas where all atoms are ionized. I would like to know if liquid or solid plasma can exist. Let’s take chemical element Lithium, its atom has got 3 electrons and Lithium’s crystal lattice is arranged like this...
  35. Krushnaraj Pandya

    Ring and solid sphere rolling down an incline - rotation problem

    Homework Statement A solid sphere, hollow sphere, disk and ring are released simultaneously from top of a incline. Friction is sufficient to prevent slipping of hollow sphere- what will reach the bottom first? Homework Equations a in pure rolling down an incline=gsinθ/(1 + I/mR^2) The Attempt...
  36. 0

    Solid of revolution -- General question

    There are two ways to revolve, around Y or X and the formulas are different. If I have something bounded by $$f(x) = x^2 + 1$$. I can write $$x = \sqrt{y - 1}$$. But, is it wrong to swap axis to show that I'm integrating dy, not dx?
  37. Dave Mata

    Adiabatic Reversible Compression of a Solid

    Homework Statement Derive an expression for the change of temperature of a solid material that is compressed adiabatically and reversible in terms of physical quantities. (The second part of this problem is: The pressure on a block of iron is increased by 1000 atm adiabatically and...
  38. F

    How a solid body emits a lower frequency photon than absorbed

    I’m trying to understand how a solid body changes the wavelength of radiation it re-radiates from that which it originally absorbed. I’m thinking in context to the way that the Earth absorbs higher frequency radiation from the sun, but when it re-emits the energy it’s at a much lower frequency...
  39. Krushnaraj Pandya

    Radiation force on a solid hemisphere

    Homework Statement A perfectly reflecting solid hemisphere of radius R is placed in the path of a parallel beam of light of large aperture, if the beam carries an intensity I, what is the force exerted by the beam on the hemisphere? Homework Equations radiation pressure=I(1+ro)(cos^2(x))/c I...
  40. Jozefina Gramatikova

    Electromagnetism and a solid metallic sphere

    Homework Statement Homework Equations The Attempt at a Solution The textbook says that the electric field on a surface of a conductor is: . So, I guess since the sphere is metallic I can assume that what I have written there is true?
  41. G

    A Energy gap between energy bands in solid state physics

    I know that Bragg reflection in solid states at the edge of e.g. the first Brillouin Zone causes standing waves at these edges, which creates a gap between the energy bands. In this picture below you can see the probability density of a symmetric (+) and anti-symmetric (-) standing wave. The...
  42. Math_Maniac

    Moment of Inertia of Solid Sphere - Proof

    So I have been having a bit of trouble trying to derive the moment of inertia of a solid sphere through its center of mass. Here is my working as shown in the attached file. The problem is, I end up getting a solution of I = (3/5)MR^2, whereas, in any textbook, it says that the inertia should...
  43. S

    I Solid diprotium saturated vapour density

    What precisely is the equilibrium vapour density of bulk solid diprotium surface now, at 2,7 K? The density of the world falls with some power of temperature (which one?). The density of saturated vapour falls exponentially. At which temperature shall the world saturate with respect to bulk...
  44. bornofflame

    [MultiVarCalc] Find the mass of the solid

    Homework Statement Let ##a > 0##. Find the mass of the "solid bowl" consisting of points inside the paraboloid ##z=a(x^2+y^2) \text { for } 0\leq z \leq H \text{. Assume a mass density of } \rho(x, y, z) = z##. Homework Equations ##x^2 + y^2 = z^2## The Attempt at a Solution [/B] mass = ##m...
  45. bornofflame

    [MultiVarCalc] Find the volume of the solid

    Homework Statement Find the volume of the solid between the cone ##z = \sqrt{x^2 + y^2}## and the paraboloid ##z = 12 - x^2 - y^2##. Homework Equations ##x^2 + y^2 = r^2## The Attempt at a Solution I drew a simple diagram to start off with to visualize the solid formed by the intersection of...
  46. H

    I What's the effect of E-field for an electron in a solid?

    Could an uniform external electrical field make an electron jump to a higher energy level?
  47. Sagar Rawal

    A Mott insulators and electron-electron insulators

    I found this paragraph from one of wiki article, "Mott considers a lattice model with just one electron per site. Without taking the interaction into account, each site could be occupied by two electrons, one with spin up and one with spin down. Due to the interaction the electrons would then...
  48. B

    Stress Used in Lagrangian Equation for Solid Mechanics

    Bathe (reference below) outlines the updated Lagrangian (UL) and total Lagrangian (TL) approaches using the second Piola Kirchhoff (PK2) stress. Others (i.e., Ji, et al. and Abaqus) define the UL and TL formulations in terms of the Kirchhoff or the Cauchy stress in rate form. This form requires...
  49. HappyFlower

    A solid disk of radius 23.4cm and mass 1.45kg....

    Homework Statement A solid disk of radius 23.4 cm and mass 1.45 kg is spinning at 43.1 radians per second. A solid cylinder of radius 12.1 cm and mass 3.33 kg is not spinning. The cylinder is dropped into the center of the spinning disk. After a short time friction has caused both objects to...
  50. A

    Specific heat capacity of a solid material

    Homework Statement A 4.80 kg piece of solid material is heated from 16.4C to 219C (3 s.f.) using 787 kJ of energy (3 s.f.). Assuming an efficiency of 0.383 for the heating process, and that the material does not melt, calculate the specific heat capacity of the material. Homework Equations...
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