Minimum Definition and 1000 Threads

  1. J

    Let f(x)=3x^2+6x-10For which input x is the value of the function a minimum?

    And what is the minimum value? ( -b/2a is for a maximum problem, but how do you get through this kind of problem?)
  2. P

    Polarization: minimum thickness for quater-wave plate

    a certain bifringement material has indexes of refraction n1 and n2 for the two perpendicular components of linearly polarized light passing through it. the corresponding wavelengths are λ1=λ0/n1 and λ2=λ0/n2, where λ0 is wavelength in vacuum. If crystal is to function as a quarter-wave plate...
  3. D

    How Do You Calculate the Minimum Radius of Curvature for a Banked Roadway?

    Homework Statement A civil engineer is asked to design a curved section of roadway that meets the following conditions: With ice on the road, when the coefficient of static friction between the road and rubber is 0.1, a car at rest must not slide into the ditch and a car traveling less than 80...
  4. C

    What is the bare Minimum Lagrangian\Hamiltonian mechanics

    I am currently trying to self learn general relativity. I understand you need knowledge of an action principle, but what I am not so sure of is how deep of an understanding I need. I currently have a book on classical field theory and I am at the point of basic Lagrangian's and holonomic...
  5. P

    Polarization, minimum thickness of a quarter wave plate

    Homework Statement show that minimum thickness of quarter wave plate is d=\lambda0/4(n1-n2 Homework Equations \lambda1=\lambda0/n1 \lambda2=\lambda0/n2 The Attempt at a Solution for quater wave plates wavelengths must differ by 1/4 i can see its simple but i just can't see what...
  6. F

    Banked road (find the minimum radius)

    Homework Statement I've already answered the first part. The second part is what's giving me trouble. Homework Equations Here's how I solved #10: Since the car is at rest, we're only worried about the force of friction and the parallel component of gravity: F_f = F_g *...
  7. B

    How to Calculate Minimum Duct Thickness for Vacuum at 150°C?

    How to calculate the minimum thickness of a duct which hold vacuum inside at 150 deg c? And what's the basic to select the stiffer size and distance between each stiffener. Thanks.
  8. P

    How Is Minimum Sensitivity Calculated in Instruments?

    Homework Statement The attempt at a solution First, we define sensitivity as the change of an instrument or transducer's output per unit change in the measured quantity. So to find the minimum sensitivity I simply plugged in the largest possible input (5.0 mm) into the equation: E =...
  9. A

    Optimizing astable multivibrator for minimum power consumption

    In short, if I want a given frequency, and I use BJT transistors, what would be the optimum capacitors and resistors in a multivibrator. Example: http://upload.wikimedia.org/wikipedi...tivibrator.svg So, what are the optimum values C1=C2, R1=R4, and R2=R3?
  10. G

    Deriving minimum escape height and velocity

    Homework Statement At which minimum height atoms or molecules are able to leave Earth’s atmosphere to space? To obtain an approximate estimate use the assumption that molecules can leave if the mean free path, λ, is larger than the scale height H. Write λ and H as a function of height and...
  11. S

    What Minimum Height Fish Must Spot Pelican to Escape?

    Homework Statement If it takes a fish 0.19s to perform evasive action, at what minimum height must it spot the pelican to escape? [Suppose a pelican starts its dive from a height of 15.9 m and cannot change its path once committed] If it takes a fish 0.19s to perform evasive action, at...
  12. R

    Probability- minimum inventory to satisfy demand

    Homework Statement There are 20 customer locations, the demand in each location is normal with mean 60 and SD 20. All 20 locations have independent probabilities. The goal is to cover all of the demand in a month at least 95% of the times. What's the minimum total inventory the company should...
  13. A

    Minimum Critical Power Ratio (MCPR) for a BWR

    From Todreas & Kazimi, Nuclear Systems I, Problem 2-3 1. Homework Statement Calculate the minimum critical power ratio for a typical 1000 MWe BWR operating at 100% power using the data in Tables 1 – 2, 1 – 3, and 2 – 3. Assume that: a) The axial linear power shape can be expressed as...
  14. L

    IRF3000 Minimum and Maximum Voltage

    Greetings! I am actually confused on what is the maximum and minimum voltage at the drain pin of IRF3000 MOSFET. Here is the datasheet: http://www.datasheetcatalog.org/datasheet/irf/irf3000.pdf Here is what the datasheet says: VDSS = 300V I wonder if this is the maximum or minimum voltage. I...
  15. A

    What Is the Minimum Launch Angle to Hit a Target 200ft Away?

    I wasn't able to figure this problem out, so I looked at the answer. The answer is 19.06 degrees and 2.116 seconds. Using these values in the kinematic equations, I calculated that at x=200 ft, the height of the projectile is y=50ft. When x=200ft, shouldn't y=0ft? I thought the problem is asking...
  16. 5

    Wire cut to shape circle and square so total area is maximum or minimum

    Homework Statement A piece of wire 40 cm long is cut into two pieces. One piece is bent into the shape of a square and the other is bent into the shape of a circle. How should the wire be cut so that the total area enclosed is a (a) maximum and (b) minimum? Homework Equations Area...
  17. S

    What Is the Minimum Power Required for a Heat Pump to Maintain 20°C?

    Hello, Just wondering if you could help me out with this question; A house is to be maintained at 20°C in winter and the heating load is 10kW. The outside temperature is -5°C. If a heat pump is to be used to heat the house, what is the minimum power required to drive the heat pump...
  18. M

    Minimum Power of the engine on a car climbing a hill

    Hi, Can someone please solve this question for me, including step by step instructions ? I can solve the ones where the mass of a car is given, but can't do this one. Homework Statement Setting off from rest the car accelerates uniformly and climbs a steep hill which has a gradient of 1...
  19. J

    Incredibly close to a modular arithmetic proof by minimum counterexample

    As stated in the title, I am trying to prove a statement by minimum counterexample involving modular arithmetic. My problem is producing the contradiction, but I feel so close! (The contradiction is p^m | (1 + p)^{p^{m - 1}} - 1) Homework Statement Let p be an odd prime and let n be a...
  20. S

    Minimum Absolute Value of a nxn Matrix Determinant

    The following matrix problem occurred to me. I figured out the answer and would like to pose the problem. It's easy but would be best for an undergrad math major. The question: Consider a square n by n matrix with entries 1, 2, ..., n squared. Find a way to arrange these entries so that the...
  21. J

    Laser focusing, minimum beam width

    I need to know the beam width of a pulsed yag laser (280.5 nm) when focused, assuming its completely guassian. The laser is focused through a bi-convex lens with f=15cm. I've found expressions for w(z), but they are all in terms of the minimum waist, w0, which I don't have and is probably the...
  22. E

    Minimum MSE estimation derivation

    Hello, Would anyone be-able to recommend a good, easy to read article which outlines MMSE and its derivation. Specifically I am having trouble finding this term + \int x'xP(x|y)dx-\left \| \int xP(x|y)dx \right \|^2 from E({\left | \left | X-z \right | \right |}^2|Y=y)...
  23. J

    Find the supremum, infinum, maximum and minimum

    Homework Statement find the supremum, infinum, maximum and minimum Homework Equations (n-2sqrt(n)) n is element of natural numbers The Attempt at a Solution no idea on how to do this help please
  24. K

    Minimum velocity to change radius of orbit

    Homework Statement A rocket is in an elliptical orbit around the earth; the radius varies between 1.12 Rearth and 1.24 Rearth. To put the rocket into an escape orbit, its engine is fired briefly in the direction tangent to the orbit when the rocket is at perigee, changing the rocket's velocity...
  25. V

    Maximizing Base Angles for a Fixed Area and Base Length

    Homework Statement The base b and the area k of a triangle are fixed. Determine the base angles if the angle at the vertex opposite b is to be a maximum. Homework Equations The Attempt at a Solution The answer the book gives is arctan(4k/b2) I looked at the solution to the...
  26. F

    Minimum Separation of Two Frictionless Pucks

    two frictionless pucks are placed on a level surface, as shown, at an initial distance of 20.0 m. the mass of puck 1 is 0.80 kg and it has a charge of +3.0 X 10^-4 C., while puck 2 is 0.40 kg with a charge of +3.0 X 10^-4 C. the initial velocity of puck 1 is 12.0 m/s (E) and the initial velocity...
  27. R

    Absolute Maximum and Minimum Values over a given interval

    Homework Statement Find the absolute maximum and absolute minimum values of the function (x^3)+(12x^2)-27x+9 on each of the following interval [-10,0] The Attempt at a Solution I got this and its saying its wrong. y'= (3x^2)+(24x)-27 factor: 3(x^2+8x-9) so x=-9 and x=-1 y''=6x+24...
  28. R

    Maximum And Minimum of a function

    Function:x+x2/3 I got 0 and -(8/27) as the criticical numbers. Am I right? I also want to know if this function as a max and a min. Note:2/3 is an exponent.
  29. E

    Finding Min Velocity for Projectile from A to B

    Homework Statement What I would like to do is find the minimum velocity needed to launch a projectile from point A to B when B is not at the same height as A. I keep finding myself stuck with two unknowns (initial speed and release angle) and I am not sure how to resolve them. If the problem...
  30. M

    Trigonometry, find the minimum of tan(a).tan(b).tan(c)

    Homework Statement 1. Given a,b,c are acute angles and a + b + c =180. find the minimum of tan(a).tan(b).tan(c) 2. Prove that if a+b+c=90, then tan(a)+tan(b)+tan(c) >= 31/2 Homework Equations The Attempt at a Solution I don't even have any ideas how should i start to find/prove them... any...
  31. C

    Minimum velocity for a sonic boom?

    On our grade 11 physics exam, there was a question asking for the minimum velocity of a jet in order for it to produce a sonic boom (the temperature of the air was given, so the speed of sound in the situation was known). According to our textbook, a sonic boom is produced only after the jet's...
  32. L

    Equilibrium: Minimum Cable Length

    Homework Statement The above figure shows a uniform iron beam of mass 253 kg and length L = 3 m. The cable holding the beam in place can take a tension of 1300 N before it breaks. Use the Young's Modulus for steel to be 200e9 N/m2. (You may ignore the small mass of the cable in this...
  33. G

    Hover bike - what is the minimum propeller rpm required?

    Hello, I read this article about someone who made a hover bike prototype from a motorbike and two propellers. Best part is, its classified as Ultralight and doesn't require a license to fly! I can totally see myself building something like that in my back garden! How can I calculate the...
  34. G

    How Do You Calculate the Minimum Cost of Constructing a Power Line?

    Hey guys I know this questions has been posted before but I still can't seem to figure it out. Thanks a lot for your help (: Homework Statement A power line is to be constructed from a town to a mine that is located near a straight road going to the town. The point on the road closest to...
  35. J

    Find minimum energy of a photon to produce 25keV electron in compton scatter?

    Homework Statement What is the minimum energy that photons must have to produce 25 keV electrons in a Compton scattering? (answer in keV) Homework Equations Not too sure here, We know Eincident= Efinal + K.E.electron We know that the work function (binding energy) is also taken into...
  36. C

    Question: Minimum uncertainty in ground state electrons

    Hey all, I'm a student curently studying in a Singaporean Junior College (American 12th grade equivalent). I was curious and just thought of the following: Suppose a system with a electron and a proton nucleus, a hydrogen atom. From electrostatic force and circular motion equations- F =...
  37. R

    Minimum radius to avoid voltage breakdown?

    I am trying to figure out the minimum radius needed to avoid voltage breakdown. I found this from a Physics website: "The electric field near a conductor is inversely proportional to the radius of curvature of the surface." So if I know the voltage and the distance between the 2 metal...
  38. J

    Maximum and Minimum in Trigonometry

    Homework Statement Find Maximum and Minimum value of Homework Equations \mathbf{f(x) = sin^{2n+1}\; x - cos^{2n+1}\; x} and \mathbf{n\in\mathbb{N}} The Attempt at a Solution put \mathbf{n=1, f(x) = sin^3\; x -cos^3\; x}\\\\ get \mathbf{-1\leq f(x)\leq 1}
  39. B

    Finding the Minimum of a Function for Calculus Students

    Homework Statement Check for minimum: When you've got your x value and sub it back into the f'(x) equation, should you get zero if it's a minimum? Homework Equations The Attempt at a Solution
  40. 7

    Mathematica Finding Minimum Coefficient of (1+x)^n for k<=20

    Hello every one, I wish i can some help in my mathematica programing. I hane k <= 20, k is + integer. n = 1/12(3(5 - 2Sqrt[6])^k) what I need to do is for every value of n (comes from K ofcourse), Print the minmum coefficient for (1 + x)^n %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%...
  41. Femme_physics

    Finding the minimum length of a median in a triangle

    Homework Statement In a right triangle ABC, AD is a Median to BC (see drawing) Given: AB+BC = 4 A) Mark BD with an x, and express the lengths of the adjacent and opposite through x. B) Find the x for which the length AD is minimal http://img641.imageshack.us/img641/6798/abctriangle.jpg The...
  42. B

    Speed of sound minimum distance problem

    Hi all, just a question I am having trouble with 1.) You're watching a carpenter pound a nail. He hits the nail twice a second, but you hear the sound of the strike when his hammer is fully raised. What is the minimum distance from you to the carpenter? assume the air temperature is 20...
  43. S

    Finding minimum distance between two points on two different parabolas

    Hi everyone. I've got a homework problem with Differential Calculus that drives me crazy for a couple of days so far and would like to ask you guys for a few suggestions Homework Statement Given two parabolas, (C1): y = x2 and (C2): y = - (4-x)2. Find two points, each point on one parabola...
  44. A

    Find the minimum distance from a curve to a point not on it

    Homework Statement You are given point (1,2). f(x) = 0.199445983x^2 - 3.789473684x + 19 f'(x) = 0.398891966x - 3.789473684 You also know (0,19), (9.5,1) <-- this is the vertex. This graph has the domain 0≤ x ≤ 9.5 Find the point on the curve that when joined to a line segment with...
  45. N

    What orientation will give the minimum mutual inductance?

    Homework Statement Suppose a fixed distance separates the centers of two circular loops. What relative orientation of the loops will give the maximum mutual inductance? What orientation will give the minimum mutual inductance? Homework Equations none The Attempt at a Solution...
  46. K

    Minimum Work Needed to Bring 2 charges from distance infinity

    Two charged particles are brought together from a great distance (r=infinity) to a distance of 2 m. The particle has a positive charge of 3.0 x 10^-5 C and the second has a negative charge of 1.35 x 10^-5 C. What minimum work was accomplished in this process? I can't for the life me figure...
  47. Z

    What is the Temperature of Minimum Density for Water?

    What is the temperature at which water possesses minimum density?
  48. B

    Find the minimum value taken by the integral expression

    Homework Statement find the minimum value taken by the integral expression integral from 0 to pi/2 [(y')^2]-(y^2)+2xy dx y(0)=0 y(pi/2)=pi/2 The Attempt at a Solution using euler lagrange d/dx(2y')-(-2y+2x)=0 2y''+2y-2x=0 from here I'm stuck
  49. J

    MATLAB Optimizing Minimum Value Search in MATLAB for Scientists

    I got a quick question, let's say I have an array of numbers for example [ 9 3 2 7 1 8 ] and I want to find the minimum value ie: for this example it would be 1. How could I implement an optimization search like this??
  50. K

    Minimum time through a cyclotron

    Homework Statement v initial is also equal to 1000 Homework Equations ? The Attempt at a Solution the only time the particle actually speeds up is during the crossing of the dees. so integral of of Vdx = the maximum energy of the system, but i don't know how to make this into an...
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