decrease Definition and 239 Threads

  1. G

    Will the fusion reactor ITER decrease entropy?

    ITER is the fusion reactor in southern France that hopefully will come online in 2018. According to wiki http://en.wikipedia.org/wiki/ITER The ITER fusion reactor itself has been designed to produce 500 megawatts of output power for 50 megawatts of input power. Does this mean that if...
  2. M

    Amount of photons released during decrease of energy of vibration

    An atom has the following energy of vibration: E= nhv. n can only be in the range of whole numbers. So if an vibrating atom changed energy, say from 6hv to 2hv, it means that 4hv of energy is released in light/photons Does that mean that 4 photons are "released" by the atom (?), because...
  3. M

    EM algorithm convergence KF log likelihood decrease

    Hi everyone, Im running the KF to learn parameters of a model, the log likelihood of the p(Y_{k}|Y_{k-1}), however decreases. Can anyone advise, does this mean my implementation is wrong or can this just be the case. Advice appreciated Thanks
  4. P

    Alpher Bethe Gamow: Factor characterizing the decrease of density with time

    Alpher Bethe Gamow: "Factor characterizing the decrease of density with time" Directly from the article: http://cache.artofproblemsolving.com/texer/images/c957650eca2c34559b5fd5931bd74440410d6ee3.png where f(t) is a factor characterizing the decrease of the density with time. What...
  5. Y

    Ideal Gas Situation: What happens when P, V decrease?

    Homework Statement If the volume V and pressure P of an ideal gas decrease, which statement is true about the internal energy IE, temperature T and the intermolecular forces IF? (I am not going to copy and paste the choices here in an effort to focus attention on the attempt of...
  6. J

    Formula for transverse decrease in signal strength?

    Alice is transmitting an electromagnetic beam to Bob. Assume it is a well collimated beam, like a laser beam, or a maser beam. As Bob's distance from Alice increases, his signal strength decreases according to the well known inverse square law. Eve, the eavesdropper, is beside the beam, not...
  7. C

    Decrease in viscosity upon rapid decelleration

    I'm in search of a material that decreases in viscosity with acceleration. In this case, I really mean decelleration, but a change of velocity nonetheless. My questions: 1. Could such a material exist? Does Such a material exist? If so, what is it? 2. Would a material with said properties...
  8. D

    In a series circuit with 3 bulbs, does the voltage decrease?

    In a series circuit with 3 bulbs, does the voltage across each bulb decrease? I know the current is the same at all points in the circuit. My book says that the brightness of the bulbs are all equal. Is this true? My idea is that the brightness will not be the same because of the resistance of...
  9. M

    Does light lose energy (frequency decrease) with time?

    This isn't a direct homework question but it pertains to a little presentation I'm working on. I was curious because answers, to some extent, seem to be all over the place. Wanted to get the opinion of physicsforums. Does light traveling through space (assuming no interactions with other...
  10. 1

    Does pressure decrease when the real volume is reduced

    What is the relationship between attractive forces and real volume of a real compared to a ideal gas? Does pressure decrease when the real volume is reduced and the attractive force is increase?
  11. F

    The decrease in volume requires the surroundings do 7.6 J of work on the gases

    1. Reacting 50 mL of H2(g) with 50 mL of C2H4(g) produces 50 mL of C2H6(g) at 1.5 atm. If the reaction produces 3.1 x 10^2 J of heat and the decrease in volume requires the surroundings do 7.6 J of work on the gases, what is the change in internal energy of the gases? 2. Change in...
  12. I

    Intervals of increase and decrease

    Homework Statement find the intervals of increase or decrease of the function f(x)= (3/(x^2+11)-1 i already find the 1st derivative f'(x)= -6x/ (x^2 +11). After that i didnt know how to proceed to find the interval. I need help for the solutions.
  13. A

    Decrease permeability of ferromagnetic materials

    Hello. I know very few things about solid state physics, so my question is very basic.. I'm just searching for a clue.. Have some of you ever heard about, or imagine a way, of decreasing the permeability of a ferromagnetic material? Not by raising temperature, but with electric field or...
  14. S

    Medical Do white blood cells increase or decrease in leukaemia?

    In leukaemia since immature white blood cells increase, do they overcrowd and decrease mature white blood cells. So does neutropenia and thrombocytopenia, leucocytopenia occur in leukaemia. Or does this deped on subtypes eg in some leukaemia B lymphocytes increase. Thanks :smile:
  15. T

    As we stretch a ductile material, does the x section area decrease

    ...in the elastic region? Or does the x section area decrease only after the yield point?
  16. A

    Why does a capacitor decrease current amplitude

    Suppose you run an AC-current through an RC-circuit. Writing it all up in terms of the complex impedance you find that the current amplitude is decreased due to the capacitor. Physically I do not understand this. How does a capacitor decrease the amplitude of the current, when the current is...
  17. Low-Q

    The bumpers on a car decrease MPG

    Hi, I have thought about how the bumpers affects the performance of the available power in a car engine. The bumper applies friction to the suspension so the car doesn't jump off a bumpy road. However, that friction will be a sort of energy loss. The questions is: How much energy loss is it...
  18. S

    Carbon Content decrease after Cold-forging process?

    Hi guys, I've come across an abnormality at work with regards to Carbon Content. The raw material used was 1010 CHQ which should have a carbon content of 0.08 - 0.13. However after going through a cold-forging process, we tested the final product and found that the Carbon Content...
  19. D

    Why will current decrease in a step-down transformer ?

    Why will current decrease when voltage increase in a transformer ? I 've just learned it and I get confused. Assume there are 2 solenoids, the no. of turns of coils in the left sides one(with AC current) is less than that in right sides.By conservation of energy, V(left) x I(left) = V(right) x...
  20. H

    MHB Calculating the Rate of Decrease in Diameter of a Melting Snowball

    Volume of a sphere: \frac{4}{3}\pi r^{3} Volume of a sphere in terms of diameter: \frac{\pi d^{3}}{6} Rate of volume: \frac{d}{d(time)}volume = -1 cm^{3}/min. Rate of diameter: \frac{d}{d(time)}10 cm = ? I'm not sure what to do at this point
  21. S

    Can plants/solar panels decrease entropy?

    If in theory there was a very efficient and powerfull refrigerator. Is it possible that a plant/solar panel could turn that heat into usuable energy, faster then what the frige uses up?
  22. S

    Why Doesn't the Water Level Decrease When an Ice Cube Melts?

    Consider a floating ice cube in a glass of water. I know that the weight of the ice cube is equal to the weight of the water displaced. This would mean that if the ice cube melted, the volume of water melted would be less than the volume of the ice cube, because ice has a lower density than...
  23. R

    Does diameter of a stable atom ever increase or decrease?

    in a chunk of a pure element like iron-would the outside diameter of the the last electron shell ever naturally change from picosecond to picosecond?
  24. C

    Increase in voltage = decrease in current?

    Increase in voltage = decrease in current?? Homework Statement Electric power is transferred over large distances at very high voltages. Explain how the high voltage reduces power losses in the transmission lines. Homework Equations V = IR P = VI The Attempt at a Solution From...
  25. G

    Van der Waals, temperature decrease

    Homework Statement I need to find a p-V region where the temperature is decreasing ## (p + \frac{a}{V^2} ) (V-b) = RT ## The Attempt at a Solution So I thought that a place to start would be ## dT = \frac{\partial T}{\partial P} dP + \frac{\partial T}{\partial V} dV < 0 ##...
  26. D

    Does not receeding of galaxies decrease entropy

    Well, First there arose a interesting question of how entropy increases when particles due to gravitation form huge mass. I guess i read john baez's online page. Heat/energy so forth concept was applied to explain it. Then, Taking its reverse, does not receeding of galaxies then decrease...
  27. R

    Show how the variance decrease as degrees of freedom/sample size get bigger

    Homework Statement Homework Equations The Attempt at a Solution I'm confused actually how to go about this. Sounds very simple, but when i do what they suggest, 'first, find the variance of (n-1)s2/σ2 i get larger variances rather than smaller, which makes no sense. should...
  28. M

    Rank ability of ligands to increase or decrease Δ in a square planar compound

    Homework Statement Homework Equations I am working on a formal lab report for an inorganic chem course and forget how to construct a spectrochemical series. I have 4 complexes, each has a single absorption band in the UV-Vis spectrum. [NiBr(Mes)(PPh3)2] 450nm [Ni(Mes)Br(bipy)]...
  29. I

    The Mystery of Voltage Increase & Current Decrease

    I mean, If an ideal step up transformer increases the voltage from 10V to 20V say, why does the current halve? I know it happens and I know the equations for it, I know to say otherwise would contradict the law that energy cannot be created. But putting the equations aside, why exactly...
  30. W

    Pressure Increase with Diameter Decrease?

    Hello, I am a firearms enthusiast. In my collection is a Gewehr 88/05. This was Germany's first smokeless issue rifle and it originally used a smaller bore than is used today in the 8mm. It was converted in 1905 to take a 0.323" bullet instead of a 0.318" bullet. The leade (free...
  31. P

    Why did entropy decrease after the big bang?

    According to the big bang model, the very early universe was at one time filled with energy. The cosmic microwave background radiation shows that the energy of the universe was very uniform. The deviation of energy in the famous CMB radiation picture taken was on average just 1 in 100,000 the...
  32. F

    Saturated absorption: decrease size of material rather than intensity of light?

    In saturated absorption, the decrease in absorption (and corresponding increase in wave transmission) is dependent on the intensity of the incoming wave. But why can't we decrease the size of saturable material, rather than the intensity of light? According to my understanding, saturable...
  33. P

    Does order increase or decrease?

    as we move forth in time, does the universe become more or less complex? is this related to the theory of thermodynamics? I just need a brief explanation I'm a bit confused. Thanks!
  34. amylase

    Why does attenuation coefficient decrease with increased energy?

    Hello. Not sure if this is the right board to post. This is not homework. I am just self-teaching quantum physics as I read a book on the topic of X-ray Physics. It has about 30 chapters in total and so far I find myself having about 3 questions per chapter. Hope you guys don't mind me asking...
  35. A

    Increase and Decrease of a function question

    Homework Statement f(x)=x — cosx, 0 ≤ x ≤ 2∏ Homework Equations The Attempt at a Solution I took the derivative of the function: f'(x)=1+ sinx, 0 ≤ x ≤ 2∏ I don't know how to determine whether it is increasing or decreasing between the interval given. What should I do?
  36. C

    How fast will the pressure decrease from a leaking gas tank?

    Hi! At my plant we have a tank filled with hydrogen gas used for cooling a generator. The tank volume is 360 m^3. We have a constant leakage of 1 m^3/h. The system pressure is about 0,4 MPa. We also have a constant inflow to the system and the ventilation in the room is good so the leakage is...
  37. P

    Hi allWhy does a molten metal solidify with decrease in

    Hi all Why does a molten metal solidify with decrease in temperature. or in other words why is a closed packed structure more stable than an amorphous liquid melt. I have read that the free energy below melting point is lesser for solid state than that of for liquid state at the same...
  38. G

    Friction & Coefficient: Overcoming Initial Restitution

    Say a person is pushing a box. The box starts at rest but eventually moves because the person's act of pushing on the box overcomes the friction between the box and the ground. Is the force of friction decreased after the person overcame the initial friction? Does the coefficient of friction...
  39. M

    What direction of r vector would decrease the potential energy most rapidly?

    Homework Statement Consider a point mass, M, at the origin and a mass, m, at the point r(vector)=(x,y,z). The gravitational force on m is F(r)= (-GmM/||r||^3)(r). For simplicity, let's set GmM=1. Note that this force is directed towards the origin. the gravitational potential is a real valued...
  40. K

    Spontaneous decrease of degrees of freedom using magnetism?

    What happens then if one has applied a static magnetic field to a heat conductor? Could the temperature increase as a result of reducing the degrees of freedom, increasing the ability for heat to be transferred from that body to others?
  41. N

    Why should Hawking radiation decrease a black hole's size?

    So from what I understand when the particle anti-particle pairs that are constantly being created and annihilated come into existence near a black hole's horizon, the nearer one can get sucked in while the further one can radiate off as though it were heat. And this radiation of energy decreases...
  42. J

    Analysis of Functions I: increase, decrease, and concavity

    Hello I need help with these problems. The direction said a. find the intervals on which f is increasing, b. the intervals on which f is decreasing, c. the open intervals on which f is concave up, d. the open intervals on which f is concave down and e. the x-cordincates of all inflection...
  43. J

    Friction increase decrease Help

    Homework Statement In Fig. 6-12, if the box is stationary and the angle θ between the horizontal and force is increased somewhat, do the following quantities increase, decrease, or remain the same? http://i.imgur.com/YcOFS.jpg a) Fx b) fs c) FN d) fs, max e) If, instead, the box...
  44. A

    Why doesn't capacitance decrease with increase in temperature?

    why doesn't capacitance decrease with increase in temperature?? It is known that conductivity increases with temperature.This is because heat provides kinetic energy to the electrons in a substance,thus increasing the rate of "flow" of electrons.Considering this,the electrons in a dielectric in...
  45. T

    Does size increase or decrease as mass approaches c?

    I'm a bit confused. Relativity states that we should observe a shortening of say a spaceship when it moves close to (c) correct? But isn't one of the reasons we can't accelerate mass to (c) because rather than reaching any higher speeds when getting close to (c) it would just increase in...
  46. Femme_physics

    Does lift force decrease as speed decreases?

    Or, to be more blunt, does "lift" force even exists in statics? I was rather surprised that our teacher told us that lift force is just as strong as the normal force in statics of an object against ground. It made me wonder just how strong is it. Does lift force decrease when speed decrease...
  47. P

    If we decrease the voltage passing through a circuit, (suppose that

    if we decrease the voltage passing through a circuit, (suppose that the amount of resistance encountered by the voltage remains the same/constant), the current passing through the circuit will be most likely to decrease as well. Similarly, if the voltage decreases (the current remains constant)...
  48. Q

    What is the derivation for decrease in g with depth?

    Homework Statement We know that 'g' decreases with height and the derivation for the formula is straight enough, but how is the formula for decrease of 'g' with depth derived? The Attempt at a Solution If an object is taken to a height 'h' above the surface of the Earth and...
  49. O

    What causes pH to decrease during fermentation?

    I was making some wine recently for my undergraduate biochemistry course and i have to explain why the pH of the wine decreased during fermentation. I am genuinely at a loss; what is responsible for this decrease in pH?
  50. S

    Rate of particle collisions with walls with decrease in temperature and volume.

    Homework Statement A sample of gas (H2) is kept within a container with a piston seal (of mass M) at the top. This piston can move freely. Let's say the pressure on the piston above it is one atmosphere. If we then put this container in a reservoir of ice then the volume of the gas will...
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