Phases Definition and 105 Threads

  1. U

    Understanding Polar Vector Plots and Phases in Vector Algebra

    Homework Statement The problem is attached in the picture. The Attempt at a Solution This looks like a vector in polar notation to me (r, θ). But the application of vectors to phases and periodicity is not even mentioned in the chapter! (Vector Algebra) I've tried to make sense of...
  2. B

    Phases of Acetone and Diphenyl at room temp

    I was reviewing a chart of Physical properties of pure substances (20 °C) Acetone has a melting point of -95°C and boiling point of 56°C so you'd assume it's solid (but obvioulsy it's liquid). In addition, Diphenyl has a melting point of 70°C and boiling point of 255°C so you'd assume it's...
  3. Z

    How Do Moon Phases Relate to Time of Day?

    ok, so I guess this is supposed to be really easy, but I just can not seem to get my head wrapped around this... I have a homework question that goes like this. Here is the link to it: http://www.apsu.edu/sites/apsu.edu/f...5_Solution.pdf If the link dosent work, it asks:In each figure...
  4. I_am_learning

    Applying Same phases to a 3 phase transformer

    while reading about sequence networks, I realized this. Suppose I apply same phase to the primary of Star-Delta transformer, say instead of applying A,B, and C phase to the three terminals, I mistakenly apply A,A and A phase to all the terminals, <Neutral is applied appropriately>. Then since...
  5. S

    Phases of water coexisting at equilibrium.

    At an equilibrium temperature, can two phases of water coexist? If so; under what conditions can this occur? Many Thanks, Stickynote.
  6. C

    Voltage spike in alternator when phases are shorted?

    inductive spiking as a viable electricity generation method? i have made a multi phase alternator to be used in a permenant magnet rotor setup , where the rectified DC output is 3V on average at the operating rate of rotation, as you can see in this video however, the AC wires leading to the...
  7. S

    Difference in signs OF PHASES of -7cos(5x-3) and -cot(3x-4)?

    Homework Statement The phase of -7cos(5x-3) is -3/5 The phase of -cot(3x-4) is 4/3 Homework Equations 3. The Attempt at a Solution [/B] Why the difference in the signs of phases? I think the phase of -cot(3x-4) should be -4/3. Its an odd function: -cot(3x-4)=cot(-3x+4) and even...
  8. P

    Adding more than two coherent sound sources of different phases

    Does anyone know how to add more than two coherent sources that have different phases? An example might be a sound source and a receiver with sound reaching the receiver directly and by two reflections via different paths - maybe off a hard floor and hard ceiling. There's a good document...
  9. E

    Interference in Thin Films, figuring out the phases

    Homework Statement I don't have a question on a specific problem, I am more caught up in the determination of the phases- I'll give a general problem to use as an example: In Fig. 35-41, light is incident perpendicularly on a thin layer of material 2 that lies between (thicker) materials 1...
  10. A

    Why different crystal phases have different colours?

    Like quinacridones or HgS and HgS \gamma. I don't understand how crystal phase can act on the resonace of the electrons...Please reference! Thank!
  11. B

    Motor wiring - will phases be unbalanced?

    Ok an easy post to settle a discussion. I have posted two rough diagrams below. One shows a 3 phase motor connected directly to the supply through a 10Amp MCB for protection and a second single phase load connected via an MCB again. Now in theory if I was remove the 2nd MCB and connect the...
  12. S

    How Does Pressure Influence the Stability of Calcium Carbonate Phases?

    Homework Statement Calcium carbonate (\mathrm{CaCO_3}) has two common crystal forms: Calcite and Aragonite. In room temperature and atmospheric pressure, the Calcite has Gibbs energy -1128.8 kJ/mol, volume 36.93 cm^3/mol and entropy 92.9 J/K/mol, and the Aragonite has Gibbs energy -1127.8...
  13. N

    What do we mean by broken symmetries when referring to superfluid he3 phases?

    What do we mean by "broken symmetries" when referring to superfluid he3 phases? I struggle to understand the concept of broken symmetries of the superfluid phases of 3He. Any insight would be much appreciated. Thanks :)
  14. C

    Understanding Moon Phases: Examples & Visualization

    I feel as though I have a good understanding of the movements of the moon, sun, planets and any other bodies out there, but there is still one thing that has been giving me trouble. My problem is finding out the phase of the moon given its position and the suns position in the sky. Can someone...
  15. J

    Waves and Phases: Understanding 90 and 180 Degrees Out of Phase

    I believe I was mitaught something in class so would like to double check. If I had two sin waves, but one was inverted, would the waves be 180o out of phase. (my teacher said 90 degress out of phase) If so, how would I draw a graph where the waves are 90 o / 270 o out of phase thanks also...
  16. nukeman

    Question about Phases of the Moon. Thanks

    Ok, here is the problem I have: Figure 2 shows the Moon in its orbit about the Earth, as viewed from space high above the North Pole. Copy the figure into your lab book and for each position A − E shade the appropriate portion of the Moon’s surface as viewed from space, NOT as viewed from...
  17. C

    Determination of Metastable phases of Alumina Using EDS?

    Is it possible to know the kind of alumina phase I have using EDS?
  18. C

    Technique to identify amorphous phases

    Hi everyone! I want to ask if anyone knows a technique that could analyze a sample, with crystalline and amorphous phases, and in some way that I could identify and/or quantify the amorphous phase (atomic elements and/or stoichiometry). I read that could be a way using EELS technique, but...
  19. B

    Exploring Standing Waves: Melde's Experiment & Wave Phases

    I am stuck on a question about standing waves: 'The diagram below show's Melde's experiment and demonstartion of a stationary wave on a string' The string has 3 full wavelengths shown, and 3 points are marked: Point A is on an antinode, Point B is on the same antinode, but very...
  20. D

    Unraveling the Mystery of Electrical Phases

    Hi, I am struggling with finding info on Electrical Phases. I understand that Single Phase is simply one ac signal, and I understand that 3 phase is 3 independent ac signals, all of which are exactly 120 degrees out of phase. My struggle comes in when I think about 220 volt dryer hookup in my...
  21. M

    Determining # of phases given two variables

    I cannot determine how to figure out how many phases of H20 are present using steam tables given two variables. I have five tables from my old thermodynamics class that are for the following: Saturated Water: Temperature table Saturated Water: Pressure table Saturated Water: Solid-vapor...
  22. I

    Mathematica How Can Transfer Matrix Method Automate Phase Matching in Quantum Mechanics?

    Just for fun I'm doing a graphical representation of a QM problem out of Merzbacher. Basically we have a regular old potential barrier, with incoming particle of energy E>Vo. I am showing that as you increase the energy, the transmission is increased, i.e. the wavefunctions in all three areas...
  23. E

    Pressure at the boundary between two gas phases which are originally sepearted

    Hi. I have got two questions... 1. How can we determine the pressure at the boundary of two gas phases (say, compressed carbon dioxide released from a can and the atmosphere) which are originally separated? If we apply the ideal gas equation on each of these two phases, different pressures...
  24. F

    Why can any two phases be connected together?

    The way I understood it and that made sense when connecting two phases together was that one of the phases was in the exact opposite range(polarity). So one phase would allow current to enter the circuit and then the other phase would allow the current back out of the circuit, back to the...
  25. DaTario

    Maximum number of mutually immiscible liquid phases

    Hi All When mixing water and oil, one produces an immiscible system of two liquid phases. Some cosmetic products for women offer three immiscible liquids, producing three liquid phases. What is in nature the maximum number of mutually immiscible liquids (that can be all put together with no...
  26. A

    What is the First Condense Phase During Isothermal Compression?

    Homework Statement I'm given vapor pressures of an assumed ideal gas: (Clausius Clapeyron.. ln(p) = -A/T-BlnT+C) I am given A, B, C for liquid and solid. And given T,melt. I am to find what the first condense phase is, and at what temperature, given isothermal compression from T>Tmelt...
  27. R

    X value closest to origin - phases difference - answer does not match teachers

    Homework Statement Two sinusoidal waves in a string are defined by the functions y1 " (2.00 cm) sin(20.0x # 32.0t) and y2 " (2.00 cm) sin(25.0x # 40.0t) where y1, y2, and x are in centimeters and t is in seconds. (a) What is the phase difference between these two waves at the point x " 5.00 cm...
  28. U

    How do different types of mixtures affect phase equilibria?

    I am doing phase equilibria in college and I don't have very good books (I am in the first semester and I haven't got the chance to get good books yet) to study from and neither am I being able to find any websites that will explain to me the basic concepts of the chapter(wikipedia goes straight...
  29. A

    Identifying Phases & Common in a 3-Phase Brushless DC Motor

    Hello Forum , i have a spindle motor from a Hard disk , it's a 3 phases DC brushless motor . This motor has 4 wires , 3 phases and 1 common , how i can know the phases and the common ? Thanks in advance. Anita
  30. J

    Adding Sinusoids of differing Magnitute & Phases

    Homework Statement Find A and \theta given that: Acos(\omega t + \theta) = 4sin(\omega t) + 3 cos(\omega t) Could someone elaborate on how to solve this. I mean it looks to me that one simply takes the magnitude of the coefficient and the inverse tangent of the same coefficients. But I feel...
  31. K

    Understanding the Basics of Wave Phases for Beginners

    Wave Phases? Wtf? Homework Statement Homework Equations None The Attempt at a Solution I managed to do the first part, but not the second part regarding phases. I don't have a clue how to work the second part out. I know that an anti-node is maximum amplitude and a node is at...
  32. M

    How Many Beta Phases Are Involved in Turkish Cymbal Making?

    I am researching Turkish cymbal making technology and I discovered and learned that they made in beta phase. Beta phase comes within % 23 to % 25 tin ratio and 625 to 780 - not exactly , you must look to diagram - degrees heat. I found few phase diagrams and it seems to me there is only one...
  33. R

    How many stages or phases in inert gas pumping? (gas pressure pumps)

    I’m a Spanish student and I have to translate a text about pumps. Since I’m not an expert in the subject and I haven’t found any useful English text about it, I would like you to help me clarify some concepts about steam or gas pressure pumps. The text says that the operation of the inert gas...
  34. T

    Producing Martensite & Bainite in Carbon Steel

    How to 'produce' martensite and bainite? For what i know, martensite formed by rapid cooling from austenite phase of steel, and slow cooling to form back to it's original state. But in order to form bainite, what's the cooling rate? intermediate between rapid and slow cooling? How rapid and...
  35. M

    Exploring Water Particle Size in Gas & Water Phases

    Hallo Everyone, I am trying to find out what happens to the size of a water particle in the gas phase and water phase. Knowing that the max molecular size of one water molecule is 2,78Angstroms, I am not quite sure at which state this dimension is valid. When combined with other molecules (a...
  36. W

    Drawing moon phases - what’s your opinion?

    The lit part of the moon in the dark sky is white, of course. What do you do when teaching on a whiteboard? If I use a blackboard, shading (with white chalk) the part that is lit make sense. However, I am always teaching on a whiteboard and using white paper in class. Therefore, I shade...
  37. B

    Analyzing Electromagnetic Radiation Intensity: N Antennas with Random Phases

    1. Consider N similar antennas emitting linearly polarized electromagnetic radiation of wavelength \lambda and velocity c. The antennas are located along the x-axis at a separation \lambda form each other. An observer is located on the x-axis at a great distance from the antennas. When a single...
  38. M

    Motion with two constant acceleration phases

    1.The cage of a mine hoist starts from rest and descends the top part of the shaft with a constant acceleration of 1m/s^2. For the remainder of the shaft the cage decelerates at a constant 2m/s^2 so that it stops at the bottom of the shaft. The total time taken for the descent is 60s. Determine...
  39. S

    Phases of SHM & Wave Motion: Are They Equal?

    My teacher told me that in SHM and wave motion phase refers to the argument in the corresponding function. then she said that if there is a difference of 2pi in the arguments then the phases are equal (sin ,cos function) but isn't it wrong , i know that their effect in terms of velocity , acc...
  40. A

    Mixing Matter: Can All Phases be Combined?

    Can all phases of matter form mixtures? I can't use wikipdia because my computer won't let me
  41. G

    Superconductivity emerging between spacially separated phases?

    Hi! I was wondering if theoretical or experimental work has been done on superconductivity being created at interface between different phases? I read a paper where they claim to have found a very thin superconducting layer between insulating oxides, but are the more sources? Especially...
  42. malawi_glenn

    Finding AGB Star Phases: Modeling S-Process in a Helium Shell Burning Region

    Hi! I have a project where I am supposed to model the s-process in a star in its Helium shell burning region, and i shall do this for a variation of neutron exposure, where neutron exposure are defined as: \tau = N* \Delta t , t is time. N is number density of neutrons. So I in...
  43. F

    Probability Amplitude phases

    Quesion in approaching to Path Integral I've just read "Quantum Mechanics and Path Integral" book which was written by Feynman, he said the phase of probability amplitude is proportional to "the ACTION S in units of Quantum of action \hbar . What is the reason to be that? Can anybody explain...
  44. A

    How Do You Calculate the Phase of a Spherical Wave at Different Distances?

    Homework Statement A spherical wave with a wavelength of 2.0 m is emitted from the origin. At one instant of time, the phase at 4m is (pi) . At that instant, what is the phase at 3.5m? What is the phase at 4.5m at the same instant? Homework Equations ∆Φ = 2π[(∆x)/λ] The Attempt at a...
  45. S

    What are some of the strange phases you went through in your youth?

    I've been listening to a lot of David Bowie lately. Particularly stuff from his early 80s "Man Who Fell to Earth" phase. Looking back at the diversity of his discography over the years, you can't help but notice that he never ceases to reinvent himself. You get the feeling that he becomes...
  46. A

    Question about light waves and phases.

    I am a sound tech and I no from my work there that if you have (in theory) two sound waves and 1 is 180 degrees out of phase with the other that they will cancel each other out. - This is mainly the basic theory of noise canceling headphones (along with some acoustic material, etc) and balanced...
  47. A

    Incommensurate phases- what is that?

    Hello! I need Your help. If anybody knows, tell me please what incommensurate phases mean. If anybody knows, give me please corresponding links. Thanks.
  48. K

    Phases of the Moon: Angular Separation Question

    Hi, Just a stupid doubt...when the moon is in FIRST QUARTER or LAST QUARTER, their angular separation is of 90 degrees; question: is it the TRUE angular separation or is it the difference of ecliptic longitudes? Kind regards, Kepler
  49. A

    FORCES LAWS: Phases, Casimir Effect, Attraction & Repulsion

    I studied about Casimir effect of attractive force, analogous to 18th century French sailors: "Where two ships are rocking from side to side in conditions with a strong swell but light wind, and the ships come closer together than roughly 40 m, destructive interference eliminates the swell...
  50. CarlB

    Complex phases in Stern-Gerlach filters.

    I found an interesting way of calculating the complex phase changes induced by a series of Stern-Gerlach filters applied to a beam of spin-1/2 fermions. It's obvious enough that I'm sure someone else has seen it before, and I was hoping someone would give me a reference. A Stern-Gerlach...
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