Solid Definition and 1000 Threads

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. J

    Crazy orientation of solid oblong

    I got these people trying to say that you can orientate a solid oblong so that it looks half the length and width with the only residule effect that it looks like it is slanted sideways a bit. Does anyone know what it is or are they crazy. I think they might be crazy. How do you explain this to...
  2. P

    Electric field lines from a solid charged sphere.?

    What would be the pattern of electric field lines 'inside' a solid charged sphere..?
  3. A

    Thermal conduction of heat by a solid body

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  4. C

    How Is the Center of Mass Calculated for a Solid Cone?

    I am using the textbook called Classical Mechanics by John R. Taylor. Z = 1/M ∫ ρ z dV = ρ/M ∫ z dx dy dz On page 89, example 3.2, it says: "For any given z, the integral over x and y runs over a circle of radius r = Rz / h, giving a factor of πr2 = πR2z2 / h2." I wish the book would...
  5. C

    Integral of differential cross section over solid angle

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  6. M

    Different ways of calculating a solid of revolution

    In my calculus exam, I would like to know for all of the questions that I am 100% right (who wouldn't?). I can be sure of this for most basic questions using my graphics calculator (fx-9750gii) and some simple maths. One thing I want to know how to be "completely sure" to solve are solid of...
  7. A

    The volume of a solid rotating about a different axis

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  8. J

    Simulation Tools for Solid State Devices and MEMS

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  9. C

    Stephan-Boltzmann law, solid angle integral, and an extra pi factor

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  10. M

    Describe the solid generated by the integral

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  11. P

    Volume of a Solid: Washers/Disks/Shells

    Homework Statement The volume of a solid obtained by rotating the region enclosed by x=0, y=1, x=y^5 about the line y=1 can be computed using the method of disks or washers via an integral.Homework Equations V= ∏\int(R^2-r^2)dx The Attempt at a Solution I have attempted this problem many...
  12. E

    How to move particles in solid?

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  13. B

    Electric potential of a solid copper sphere

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  14. L

    Constructing a Solid Klein Bottle

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  15. J

    What Could Cause Odd Failures in a Solid State Relay?

    I'm not that familiar with the inner workings of solid state relays, and I'm seeing an unusual anomaly in my circuit that I'm not quite sure how to explain. For my job, I'm running tests on some sensors. One of the requirements for the test is to turn the power to the parts on and off...
  16. L

    Solid Mechanics- Ultimate Load in truss.

    Homework Statement A 3/4-in.-diameter rod made of the same material as rods AC and AD in the truss shown was tested to failure and an ultimate load of 29 kips was recorded. Using a factor of safety of 3.0, determine the required diameter (a) of rod AC, (b) of rod AD. Homework Equations...
  17. mesa

    Moment of inertia question; tube, solid cylinder on inclined plane.

    If you have a tube and a solid cylinder of the same dimensions and density and rolled them down an inclined plane the 'tube' would cover the same distance in less time?
  18. R

    Electric field inside a solid sphere

    Homework Statement We have a uniformly charged solid sphere whose radius is R and whose total charge is q. I'm trying to find the electric field inside a (r<R). The correct answer must be: E=\frac{1}{4 \pi \epsilon_0} \frac{q}{R^3} r \hat{r} How did they get that answer? The Attempt at a...
  19. R

    Qualitative Solid Spherical Conceptual

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  20. C

    Finding the volume of a solid revolution (shell method)

    Let f(x)=9-x^2. Let A be the area enclosed by the graph y=f(x) and the region y>=0. Suppose A is rotated around the vertical line x=7 to form a solid revolution S. So, using the shell method, I was able to find the indefinite integral used. I found the shell radius to be (7-x) and the shell...
  21. Spinnor

    Heating an elastic solid by stressing it verses it's hardness.

    I bought a cheaper set of roller blade wheels (you get what you pay for). With new wheels installed I had to work much harder to take longer on my usuall route. The new wheels had a hardness of 82a. The original wheels had a hardness of 80a and the last set had a hardness of 85a. The new wheels...
  22. P

    Estimating the volume of a solid

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  23. M

    Change of relative permittivity of liquid and solid water

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  24. R

    Center of mass of a solid hemisphere (where's the error)?

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  25. T

    Electric field at points from a solid copper sphere

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  26. H

    Java Java3D graphics: solid line looks dashed

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  27. F

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  28. N

    Total Solid Angle of 6 Squares on Unit Sphere

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  29. M

    How Is the Solid Angle for a Circular Detector Calculated?

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  30. L

    Finding the potential of a charged, solid sphere using the charge density

    Homework Statement Solid ball of charge with radius R and volume charge density ρ(r) = ρ0r2, centred at the origin. I have already found the electric field for r<R and r>R and also the potential at the origin by using the formula: V = -∫E.dl Now i want to find the potential at the...
  31. N

    Volume of the solid using a cylindrical cross section

    Homework Statement Find the volume of the solid obtained by rotating the region bounded by the given curves about the specified axis. Homework Equations y = \sqrt{x-1} , y = 0, x = 5; about y = 3 The Attempt at a Solution I already completed graphing it, but not really sure how...
  32. D

    Introductory Solid States Physics book?

    Hi, I'm taking an introductory course on solid state physics next semester, and the book the Professor has chosen is the 8th edition of Kittel. I have heard MANY bad things about this book, so I'm wondering if I should just use an earlier edition or another book entirely. Any...
  33. Y

    Natural Frequency of Solid Spheres

    Dear Physics Forum community, I am posting here as a last resort, so any guidance/references would be much appreciated. As a small part of my project, I need to calculate the natural frequency of metallic solid spheres. All I have been able to find on the web is the Schummann Resonance...
  34. T

    Is a Computer with No Moving Parts Truly 100% Solid State?

    Other than the fan and hardrive, nothing else seems to be moving...
  35. N

    Surface area of a solid of revolution

    Homework Statement Having recently learned the disk/shell/washer method for finding the volume of a solid of revolution, I'm trying to apply similar methods to derive the formula for the surface area of a cone (and hopefully after that, that of a sphere). The region that is revolved around...
  36. B

    Energy waves from impact in a solid

    So I'm supposing a scenario where you have energy transfer into a solid and waves propagating out from the impact point and i want to measure the energy at different distances from the "epicenter" with sensors. the relationships I've been pointed to are basically conservation of energy at the...
  37. O

    Finite Element Stress Analysis: Best Way to Get Accurate Results?

    What's the best way to do Finite Element stress analysis? By that, I mean I'm looking for the best set of general fundamental assumptions to start with. In your opinion. I ask because I'm trying to write a computer code in Matlab that I can use as a general tool for who-knows-what sort of...
  38. fluidistic

    Estimating the average time between collisions (electrons in Cu solid)

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  39. S

    Calculate Dead Load of Beam w/ Solid Square Cross Section

    Homework Statement A beam has a solid square cross section of 100mm and is simply supported by two supports 3m apart. Calculate the dead load that can be safely supported when applied to the middle of the beam. Homework Equations Solid square cross section of beam: 100mm Material...
  40. S

    Find the moment of inertia of a solid sphere.

    Homework Statement Beginning with Icm = Integral of r^2 dm from r1 to r2, find the moment of inertia of a solid sphere about any tangential axis. Homework Equations Icm = Integral of r^2 dm The Attempt at a Solution I set up the infinitesimally mass of an infinitesimally...
  41. fluidistic

    X-rays diffraction in a solid, Bragg's law

    Homework Statement The X-rays diffraction diagramm of a cubic crystal shows lines for the following angles 2 \delta = 31.47º, 39.74º, 47.58º, 64.71º and 77.59º when the X-rays have a wavelength of 1.54 \times 10 ^{-10}m. Determine the crystal stucture of the net, the Miller indices of the...
  42. fluidistic

    Solid state physics, exercise about reciprocal lattice

    Homework Statement Hi guys, I don't reach the correct answer to an exercise. I'm following Ashcroft's book. I must find that the reciprocal of the bcc Bravais lattice is a fcc one and the reciprocal of the fcc Bravais lattice is a bcc one. Homework Equations If a_1, a_2 and a_3 are...
  43. C

    What determines specific heat capacity of a solid?

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  44. M

    A solid steel shaft is subjected to a torque of 45 KN/m.

    A solid steel shaft is subjected to a torque of 45 KN/m. If the angle of twist is 0.5 degree per meter length of the shaft and the shear stress is not exceed 90 MN/m^2 (I) find the suitable diameter of the shaft . Take C = 80 GN/m^2 (II) Maximum shear strain we can solve the question by...
  45. I

    Complex Analysis or Solid State Electronics?

    First post. Great to be here. :) So, I'm stuck in deciding which of these courses to take next semester. I'm a current rising sophomore at UT Austin who has just switched from EE to physics-still nervous about that decision, but that's a separate topic. I've already got Waves(the first...
  46. A

    Determining concentration of a particular substance in a solid?

    This question may sound a bit odd, but is there a relatively simple way(by simple, I mean inexpensive) to determine how much acrylamide is in a certain type of food(e.g. French fries, potato chips)?
  47. J

    Best solid state physics video course

    Hi, What is the best solid state physics video course available online. So far the best one i have found is this one .. but it is just introduction to Solid State Physics
  48. K

    Use brutal force to find E field inside a uniformly charged solid sphere

    Homework Statement Use direct integration to find electric field inside a uniformly charged non-conducting solid sphere. The radius of the sphere is R, observing point is at a way from center of the sphere while a<R. Homework Equations Use Coulomb's law only. No Gauss law is allowed. You may...
  49. P

    Degrees of freedom of an oscillator in an Einstein solid

    I was reading through a book on statistical physics when i came across this sentence: "An Einstein solid has two degrees of freedom for every oscillator." How is this possible? I picture an oscillator (ex. mass on spring) to move only in one dimension, thus one degree of freedom. Where does...
  50. D

    Volume of Solid (Washer Method)

    Homework Statement Just need to verify that my working is correct ^^ Need to find the volume given by the region of the xy-plane that is bounded by the curves x = 0 and x = y − y2 . Rotated about y-axis Homework Equations The Attempt at a Solution I used the disk method. V = pi...
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