What is Unit: Definition and 1000 Discussions

UNIT is a fictional military organisation from the British science fiction television series Doctor Who and its spin-off series Torchwood and The Sarah Jane Adventures. Operating under the auspices of the United Nations and initially led by Brigadier Lethbridge-Stewart, its purpose is to investigate and combat paranormal and extraterrestrial threats to Earth. Several UNIT personnel (such as the Brigadier, Sergeant Benton and Mike Yates) played a major role in the original Doctor Who series, and it was a regular feature from The Invasion (1968) until The Seeds of Doom (1976).
Originally referred to as the United Nations Intelligence Taskforce, executive producer Russell T Davies said in 2005 that the UN was no longer happy to be associated with the fictional organisation and the UN's full name could now no longer be used. However, the "UNIT" and "UN" abbreviations could be used as long as it was not explained what the letters stood for. In 2008, he announced that the organisation's name had been changed to the Unified Intelligence Taskforce. This new name was first mentioned on-screen in "The Sontaran Stratagem", also in 2008, in which it was indicated in a line of dialogue that the United Nations still supports UNIT with funding.

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  1. jegues

    Signals unit impulse response h(t) ECHO

    Homework Statement a) Find the unit impulse response h(t) of an audio system that causes two echoes, one occurring at 0.5 seconds and the other one at 1.5 seconds. Please sketch H(w). (Magnitude and phase) b) Design a system that can eliminate noise coming from the 60Hz power signal (thus...
  2. S

    Abstract Algebra: Rings, Unit Elements, Fields

    1) Show that (R,*,+) is a ring, where (x*y)=x+y+2 and (x+y)=2xy+4x+4y+6. Find the set of unit elements for the second operation. I understand that the Ring Axioms is 1. (R,+) is an albein group. 2. Multiplication is associative and 3. Multiplication distributes. I just don't understand how to...
  3. U

    Identifying a ventilation unit

    Hi all; an easy question for you. In the following picture, what is the ventilation box in the corner near the floor? Is there a particular name for these things? I see them everywhere. http://upload.wikimedia.org/wikipedia/commons/7/76/Duracraft_pedestal_fan.jpg Thanks!
  4. P

    Finding Polar Unit Vectors from Cartesian Vector - Pete

    I have a worksheet that due to missing the lecture I'm now stuck on. You are given a cartesian vector and told find the polar unit vecors and hence express the original vector as a linear combination of the polar unit vectors just found. I've searched resources online but feel that there is...
  5. N

    A Unit Amplitude Polarized EM Wave Solution?

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  6. A

    Mechanical force on unit area of charged conductor.

    Homework Statement OK first, I didn't know where to post this since it is and is not homework,anyways, posting here would be safest. Now, the attached scan is a proof from my (not so trustworthy) textbook and I have some doubts in it. The first doubt is in statement S1 : Every element...
  7. I

    Calculating volume flow rate per unit width of a plate ( Fluid Mechanics )

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  8. R

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  9. D

    Dobson unit - caclulation problem

    calculate the number of DU assuming that the entire atmospheric O3 column is at a uniform concentration of 3*10^12 molecules/cm^3 between 15 km and 30 km and zero elsewhere. I have no idea how to solve it. I don't know how to convert the 3*10^12 molecules/cm^3 to units of molecules/cm^2 that I...
  10. L

    Find Max Potential Energy per Unit Length of Wire

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  11. S

    What is a scrumple unit? (pressure)

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  12. D

    Archived Estimate nuclear energy generation rate (formula given) per unit MASS MASS?

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  13. M

    How this unit comes like that ?

    How this unit comes R = specific volume X (pressure / Temperature ) 0.9m^3/kg (1.3X10^5 N/m^2 / 408 K ) R = 286 KJ/KgK please can anyone explain to me how the unit ( KJ/KgK ) comes ??
  14. mcodesmart

    What is probability per unit time

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  15. R

    Failure of a steel shelving unit

    I am currently working on a project to determine how much weight a mild steel shelving units can support. This is a project for a friend and for my own interest. I am having trouble deciding exactly what is necessary to determine the weight the shelving units will hold. Each shelf on the unit...
  16. C

    Calculating radius of Rubidium in unit cellHelp.

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  17. Crazymechanic

    Tangential force unit conversion

    Hi , if we have a rotating centrifuge at rpm "a" and we have the radius "b" of the centrifuge and then at the side i have a metal ball that weight's "c" I take the formula which you suggested me here F=ma where a=v2/r and out of that I get Newtons, how do i convert them to like pascals? Because...
  18. F

    Derivative with respect to a unit vector: is my computation right?

    Hi all! I must compute a derivative with respect to the components of a unit vector \hat{p}^{i}. In spherical coordinates, \hat{p}^{1}=\hat{p}^{1}(\theta,\phi)=\cos\theta \sin\phi I want to express the derivative \frac{\partial}{\partial\hat{p}^1} as a combination of...
  19. karush

    MHB What is the Optimal Production Level for Minimizing Average Cost per Unit?

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  20. W

    Converting Measurements for Paint: A Unit Conversion Challenge

    Homework Statement Homework Equations 1 Liter is 1000cm^3 1 foot is .3048m centi is 10^-2 The Attempt at a Solution convert ft to m 400ft * .3048m/1ft = 121.92m convert m to cm 121.92m is 12192 cm 12192 cm is 12.192 Liter 1 gal = 3.78541 L I look at the appendix but there is no equation...
  21. N

    SI Units for Pressure: N m^2 or N m^-2?

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  22. L

    What is a Newton Unit? Explained Here

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  23. I

    Question about the uncertainty principle and unit cell in phase space

    In statistical mechanics, nearly all the textbooks say that the volume of the smallest cell in the phase space of a N-particle system is h^{rN} where h is the Planck Constant, r is the degree of freedom. Also these books say that this comes from the uncertainty principle. However, the...
  24. E

    Unit step response of RC high pass filter

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  25. A

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  26. C

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  27. L

    Natural Unit Confusion: M=1/L or M=T/L^2?

    If we set c=G=1, then c=1 leads to L=1/T , the G=1 means that M=L^3/T^2 and combining the two means that M=L=1/T so far so good. But say if I also want \hbar=1 this seems to imply M=T/L^2 but combining this with c=1 which gave the L=1/T now suggests that M=1/L=T . Which seems...
  28. jegues

    Convolution of Unit Step and Impulses

    Homework Statement Homework Equations The Attempt at a Solution See the 2 figures attached below. Am I doing this correctly? Is the result I obtained correct? Is there a easier way I could've solved this problem? Thanks again!
  29. S

    Confusion about Unit Cell Structure: Understanding Lattice and Basis Vectors

    Greetings everyone, I am taking a course on elementary condensed matter physics and our textbook is "Introduction to Solid State Physics" by Charles Kittel. I have read the crystal structure from 4 books; however, I am still confused about the definitions such as unit cell, primitive vector and...
  30. J

    Showing a polynomial has at least one zero outside the unit circle.

    The first thing that we should notice is that the leading coefficient $a_n = 1$. I was thinking about considering the factored form of p. I googled, and there is an algorithm called the "Schur-Cohn Algorithm" that is suppose to answer exactly this, but I can't find any information on it or...
  31. H

    Why is the unit normal of a sphere important in vector calculations?

    I was looking at this example: http://keep2.sjfc.edu/faculty/kgreen/vector/block3/flux/node10.html and was confused between the difference between \hat{}n and \vec{}r Why is the original vector field not given in terms of a unit vector? And what difference does this make? Thanks :)
  32. N

    Finding Unit Normal to Curve Defined by Parametric Equation

    Hi, I have a curve defined by following parametric equation \begin{equation} \gamma(\theta) = 1 + 0.5 \times \cos (N \theta) (\cos(\theta),\sin(\theta)), 0 \leq \theta \leq 2 \pi \ \end{equation} where N is an integer. x and y coordinate of any point on the curve are simply...
  33. J

    Truly Bizarre - The unit tangent and unit normal vectors aren't orthogonal

    OK, this looks like a differential geometry problem, which it is, but at the end of the day I am trying to figure out why the unit normal and unit tangent vectors to a curve aren't orthogonal, so even if you don't know about DG, please respond. Obviously the two choices for E_1 and E_2...
  34. S

    Exploring the Smallest Unit of Time for Acceleration

    Is there a quantum of time? What’s the smallest interval of time in which acceleration can place? – on the earth? – on the sun? – on a black hole? A chronon is the time that light takes to cover classical electron radius. The other is the Planck time. But these won't serve my purpose, when I...
  35. N

    Express F as a unit vector and find the Scalar Projection of F onto OA

    Homework Statement Express the 5.2-kN force F as a vector in terms of the unit vectors i, j, and k. Determine the scalar projections of F onto the x-axis and onto the line OA. I have attached an image of the problem. Homework Equations Fx = Fcos(θ) Fy = Fcos(θ) Fz = Fcos(θ)...
  36. M

    Is 0.27 nN/nm equal to 270N/km in unit conversion?

    Hi everyone, I'm having a little confusion here: I measured a value which is 0.27 nN/nm and I converted it's value as 0.27 N/m. Is this correct or should it be 0.27 nN/nm = 0.27*10^9 N/m Thanks for your help
  37. L

    Homemade Radio Unit Question

    First, I know nothing at all about this topic, which is why I'm looking for help. I'm interested in building a radio transmitter/receiver like a child locator at home. The difference would be I'd like the receiver to beep rather than the transmitter, if that's even the correct language to use...
  38. A

    Derivative of Unit Vector in Three Dimensions

    Homework Statement Let r=(x,y,z). Find ∇r(hat). Homework Equations r(hat)= (x,y,z)/sqrt (x^2+y^2+z^2) ∇f=df/dx x + df/dy y... The Attempt at a Solution Okay I'm having a complete brain freeze at the moment. I know the denominator is a magnitude but am I still supposed to use the...
  39. S

    Finding values to make a unit vector

    Homework Statement Find all values of a such that w=ai+\frac{a}{8}j is a unit vector. Homework Equations unit vector has length of 1. and for a vector v unit vectors would be v/magv The Attempt at a Solution 1=magw=\sqrt (a2+(a/8)2) 1=a2+(a2/64) 64=2a2 32=a2 a=\sqrt{32} i know...
  40. P

    Easy-acceleration with unit vectors

    Homework Statement r1=(0m) r2=(2000i + 1000j)m v1=(200j)m/s v2=(200i-100j)m/s Homework Equations tantheta=vy/vx v2^2=v1^2+2ax v2=v1+at x2=x1+v1t+1/2at^2 The Attempt at a Solution Thank you for any help
  41. A

    Scientific Notation and Unit Conversions

    "The average wavelength of white light is 5.0 x 10-7m. What would this be in nanometers? The textbook answer key stated the answer as 500n but I have no idea how that is the answer. I know that the value of nanometers is 10-9 so I figured you add -7 and -9 to get -16... Thanks,
  42. M

    Unit Conversion: SI to British Units with Real-Life Consequences

    Homework Statement This is the question Still think that unit conversion isn't important? Here is a widely publicized, true story about how failing to convert units resulted in a huge loss. In 1998, the Mars Climate Orbiter probe crashed into the surface of Mars, instead of entering orbit...
  43. R

    Prove roots lie inside the unit circle

    Homework Statement Let P(z)=1+2z+3z^2+...nz^(n-1). By considering (1-z)P(z) show that all the zeros of P(z) are inside the unit disk Homework Equations None given.. The Attempt at a Solution Well (1-z)P(z) = 1+z+z^2+...+nz^n and to find roots I set it to 0: 1+z+z^2+...+nz^n = 0...
  44. P

    Advanced physics probelm involving conservation, from six ideas Unit C textbook

    Homework Statement A neutrino must pass within about 10^-18m of a quark to have any chance of interacting with it. Thus, the maximum target area that a quark presents to a neutrino is about 10^-36m^2. However, a neutrino moves so quickly and the weak interaction is so weak that...
  45. S

    Modal Analysis of AC Unit: Refrigerant Considerations?

    For doing modal analysis of suction and discharge side of an air-conditioning unit, is it needed to consider the inside refrigerant?
  46. G

    Electricity Question for Unit 2 Edexcel

    Homework Statement If lightning strikes a tree such that there is the same current through it as there was through the lightning conductor, then a much larger potential difference exists between top and bottom of the tree. Explain why this is so. The Attempt at a Solution Is this...
  47. M

    How do you calculate cost per unit of electricity?

    How do you calculate cost per unit of electricity over a certain time that a generator produces?
  48. S

    Help please .Transmission line parameters in per unit

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  49. A

    How was a unit of energy first defined?

    How was a unit of energy first defined? I know we measure energy in units of Joules as named after James Prescott Joule and a Joule is defined as 1kg*(m/s)^2 But I can't find any information on the history of the unit itself, how and when was it first defined, by whom? How was it decided or...
  50. azizlwl

    Why m.N is not a Unit of Torque

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