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.

View More On Wikipedia.org
Recent contents Top users
  1. S

    Is there a smallest unit of gravity?

    Is there a singular, smallest unit of gravity between 2 objects? For example, is it possible that a speck of dust on Earth, and a speck of dust on the opposite side of the universe, in the farthest away galaxy will have no gravitational attraction to each other? Or does the gravity will always...
  2. T

    Convergence on the unit circle

    Homework Statement Determine the behavior of convergence on the unit circle, ie |z| = 1 of: Ʃ \frac{z^{n}}{n^{2}(1 - z^{n})} Homework Equations Obviously this is divergent then z is a root of unity. The question is what happens when z is not a root of unity. The Attempt at a...
  3. K

    Plot the sequence on the unit circle.

    Consider the sequence (n) n=1 to infinity. Plot the sequence on the unit circle: n modulo 2*pi for n≥1. What do you see? Attempt: I really honestly have no idea what to do. We are learning in class about limit laws and how to prove them, so this question seems to be coming out of nowhere. :(
  4. R

    Unit Normal always pointing toward concave side

    Physically/conceptually, I understand why the unit normal vector will always point toward the side of concavity on a curve. It's because the unit normal's direction is the derivative of the unit tangent, and the unit tangent's change in direction is always toward the concave side. But how is...
  5. L

    What is the density of a unit cell of NaCl crystal?

    Knowing the atomic weights of Na+ and Cl- are 23 and 35.5, respectively, calculate the density (g/cm^3) of NaCl crystal. Hint: Avogadro’s number N = 6.02 x 10^23 is the number of atoms in one mole (weight of 1 mole = atomic weight in grams) unit cell is Face centered unit cell contains a...
  6. A

    A silly question about unit tangent and unit normal

    I know how to obtain the unit tangent, it is very easy. But for the case of unit normal, I am confused. Usually we need to know \vec{T'}(t) and |\vec{T'}(t)| in order the find \vec{N}(t). However are there any quicker method to do it? Since I saw the textbook do it without step, it seems...
  7. J

    Automation Testing Unit Control Panel: Need Help!

    Hi, I am building control panel for automation testing unit. - Ambient Temperature to measure:- - pulley speed and temperature to measure. So far... for Ambient Temp I have used T-Type and for pulley speed I have used magnetic pick up 10V. And for interfacing used USB6009. Can...
  8. L

    Is there any quantity in physics that has the unit kg^2 in it?

    Is there any quantity in physics that has the unit kg^2 in it?
  9. Phrak

    Vacuum permittivity as a fundemental dimensioned unit

    As the usual argument goes, as I understand it, everything can be expressed in units of G, h and c. (though this argument exclude the particle masses from consideration.) The permittivity of the vacuum seems to be independent of G,h,c. Am I wrong?
  10. W

    Unit analysis - using measurements as variables - correct (?)

    Homework Statement Currently, I'm expected to find the side length of a square garden whose area is 25cm2. Of course, we're talking about a square here, and since the area of a rectangle is l * w, and, when talking about a square, l = w, the area of a square is S2. Of course, I know each side...
  11. A

    Visualising atomic orbitals in a unit cell (software for making figures?)

    So I usually use VESTA to make my figures, and though the new version is able to do many mad things with calculated electron density isostructures and whatnot, I can't seem to just be able to throw in some clover-leaf d or p orbitals like what was done in the image below (from this paper on...
  12. E

    Solving Vector C with Unit Vectors | Cross Product Help

    Homework Statement use unit vectors to express the vector C where C=3.00A-4.00B the answer is apparently C=12.0i + 14.9j Homework Equations cross product The Attempt at a Solution i have no idea where to even start how is it possible to find the i orj because i don't even know...
  13. G

    Calculating maximum amount of water vapor per unit volume

    Homework Statement Compute the maximum amount of water vapor per unit volume that air can hold at the surface, where Ts = 288 K, and at a height of 10 km where T = 220 K. Express your answers in kg m-3. Homework Equations e_{s}=Ae^{\beta T} e=\rho _{v}R_{v}T The Attempt at a...
  14. M

    Surface Integral: dot product of two unit vectors

    Hello. :smile: I understand most of the work involved with these types of questions, but there is one point in an example I'm following that I don't understand. Homework Statement Evaluate: I = \int{(z^2)}dS over the positive quadrant of a sphere, where (x,y > 0). Homework...
  15. A

    Impulse and Momentum, their unit and relationship

    Homework Statement Impulse is defined as: force x time a) Find its unit expressed in term of the base units. b) What quantity has the same unit? What could it mean? (Impulse = change in momentum) Homework Equations I = F x T P = mv The Attempt at a Solution a) First, we...
  16. T

    Medical Does Vitamin E Help Prevent Strokes and How Does It Impact Blood Thinning?

    Vitamin E (alpha-d-tocopherol) has been shown to prevent creeping arterial occlusion*, increasing cerebral circulation and decreasing the risk of ischemic strokes at a minimum effective dose of 100IU/day**. As a blood thinner (anti-coagulant) it has been shown to increase the risk of hemorrhagic...
  17. A

    Unit vector in polar coorindate

    In rectangular corr. 3i+j mean leght in x-direction =3 in y-3direction =1 However, how about in polar coorindate? 3r+1\theta (r and \theta are the unit verctor in polar coor., I don't know how to type it out, I hope you understand.) Dose it mean a line with length 3 from origin and angle...
  18. T

    How do I choose the correct angle when graphing vectors from unit notation?

    Homework Statement Draw the following vector. Label the angle that specifies the vector's direction, then find its magnitude and direction. Homework Equations vector a = 2.0i - 6.0j The Attempt at a Solution I get stuck here: I don't know which angle to use.
  19. N

    Unit Vector Perpendicular to a Triangle?

    Homework Statement Given: P=(1,-2,3), Q=(-4,2,5) and S=(2,1-4) Find a unit vector that is perpendicular to triangle PQS Homework Equations Cross and Dot Product The Attempt at a Solution Correct me if I'm doing wrong. I have two solutions that I've thought: 1)What I...
  20. A

    How can A be expressed in terms of n as a unit vector?

    Homework Statement Let A be an arbitrary vector and let n be a unit vector in some fixed direction. Show that A=(A.n).n+(A*n)*n Homework Equations The Attempt at a Solution I know that (A.n).n gives component of arbitrary vector, assume that it equals to Ax
  21. W

    Understanding an Exercise on LTI Systems with Unit Sample Response

    Hello, am having an understanding problem, about an exercice on LTI systems with unit sample response. i've been given the graphical depicted output y[n], and the following output x[n]= u[n]-u[n-2] the system is as follow x[n]----> h1[n]----->h2[n]------>y[n] with h2[n]= s[n] - s[n-1]...
  22. H

    How to show only multiples of unit energy are allowed in QHO by ladder operator

    I'd like to know how to do it without solving via Hermite polynomials, so that I can check by both methods when I solve other problems. I have tried to figure out myself but I need some help. Let's say H:=x^2+p^2 , and a:= x-ip . So that [a,a^+]=2\hbar , H a \varphi_i = (E_i -...
  23. I

    Is this a trick question or is it just that simple? (magnitude and unit vector)

    Homework Statement okay i don't have the exact problem in front of me right now but it went something like this: they gave the force, F, which equaled 500 N. for part a they said to express in terms of a magnitude times a unit vector. for part b they wanted the force expressed in orthogonal...
  24. spareine

    Why is the kilogram the base unit of mass, instead of the gram?

    Why is the kilogram the base unit of mass, instead of the gram? http://en.wikipedia.org/wiki/Cgs_system_of_units" explains the replacement of the cgs- (centimeter-gram-second) by the mks-system (meter-kilogram-second) by: "The values (by order of magnitude) of many cgs units turned out to be...
  25. Y

    Some help with Si Unit conversions

    Some help with Si Unit conversions :) Homework Statement 762 Mg/m to ng/µm Homework Equations Si unit conversions The Attempt at a Solution How do I know where to place the variables? Can someone give me a tut or written explantion on how to do this?
  26. A

    Why is my transformerless converter unit failing?

    Hi all, I'm trying to build a transformerless converter unit, that will take an input of 240v a.c, and will output 12v d.c. I used a voltage divider to get a 16v from the a.c supply of 240v and connected my rectifying circuit across the 16v. I got an output of 14.59v. But on connecting the...
  27. 1

    How Do You Add Vectors Using Unit Vector Notation?

    Homework Statement Consider the following vectors: a = (5.0m) i + (2.0m) j b = (-14m) i + (6.0m)j Sum of a+b in unit vector notation? Homework Equations The Attempt at a Solution I'm not sure about this notation, all I know about adding vectors is graphically. Does (5.0m)...
  28. 2

    How to Convert Ideal Gas Constants from Mass-Based Units to Molar-Based Units?

    [SOLVED] Ideal gas unit conversions Homework Statement The ideal gas constants used in this text are typically mass-based: kJ / (kg*K). It is more useful to have them in units of kJ / (kmol*K). How to convert them using data from this text? Homework Equations The Attempt at a...
  29. L

    Is the unit of torque Nm or Nm/°?

    Hello everybody Normally you say that the unit of torque is Nm but could also be (Nm)/°.? I'm claiming this because of the fact that you normally do not give radians any unit, and that is why you just write Nm and not (Nm)/rad. SI claims that: "torque may be thought of as the cross...
  30. M

    Gradient, unit normal in vector calculus

    Homework Statement there is a surface xy3z2=4. What is the unit normal to this surface at a pt in the surface (-1,-1,2)?? Homework Equations what is a unit normal to a scalar region? how can it be calculated? The Attempt at a Solution i calculated the gradient (del operator) of...
  31. C

    Unit Conversions: kJ/mol to kJ/litre

    Let's say I have 4163 kJ/mol of energy coming from a substance with molar mass 86.14g/mol. How would I convert the 4163 kJ/mol of energy to kJ/litre? Thanks.
  32. X

    Why E's representation marix is unit matrix

    In group representation theory, identity element's representation matrix is unit matrix. But why? Could you give me an exact explanation? Thany you.
  33. J

    Defining and Understanding Continuous Unit Normal Fields on Orientable Surfaces

    So I've been reading about orientated surfaces lately, and I always see the definition that a surface S is orientable if it is possible to choose a unit normal vector n, at every point of the surface so that n varies continuously over S. However, what does "varies continuously" mean? I never...
  34. T

    Complex numbers on unit circle

    Homework Statement Let z1; z2; z3; z4 be four complex numbers on the unit circle (i.e., |z1|=|z2|=|z3|=|z4|=1). It is known that z1+z2+z3+z4=1+i . Find the value of 1/z1 + 1/z2 + 1/z3 + 1/z4 Homework Equations 1/z = barZ/|z|^2 The Attempt at a Solution I've been trying for about a day now...
  35. S

    Difference between Primitive cell, unit cell and a wigner-seitz cell.

    Hi to all experts! I know individually about primitive cell("It has lattice point at corners only") and unit cell("It has lattice point at corners as well as at center if bcc or at faces if fcc or at bases if it is base centered") Are these right? But I don't know what is Wigner-Seitz cell...
  36. I

    Optimize function over unit ball

    Homework Statement Find the maximum and minimum value of the function, defined over x2 + y2 + z2 \leq 1. x \geq 0, y \geq 0, y \geq 0. Homework Equations f(x,y,z) = xy(z+1) The Attempt at a Solution \nablaf = (y(z+1), x(z+1), xy) = 0 Gets me (0, y, -1), (x, 0, -1), (0, 0, z) and...
  37. M

    Suggstion required for setup of a 3MW Power Generation Unit.

    Hello everyone, I represent an iron & steel manufacturing industry which runs on electricity. Currently our electricity consumption is 1,000,000 units/month @ 5.5 INR/Unit consumed along with maximum kVA reached during the time of manufacturing of product which is affecting the costing of...
  38. X

    Mathematical Solution for Unit Time Step Signal with Plotted Coordinates

    Homework Statement Solvinf the unit time step equation mathematically. Homework Equations x(t) = u(t+1) - 2u(t) + u(t-1) The Attempt at a Solution How can i solve this signal mathemtically :( and using plotted signals , i couldn't understand, here is my approach and I'm...
  39. U

    Unit reduction is not making sense, what's going on?

    I am using an equation that states that critical sonic velocity is: a_{cr}=\sqrt{\frac{2\gamma}{\gamma+1}gR_{gas}T'} The units should result in velocity (\frac{m}{s}) Yet, when I do the unit reduction I do not get that answer. Here is what I get: Lets ignore the square root for now. Also...
  40. H

    Unit Conversion: G 6.67x10^-11 m^3*s^-2*kg^-1 to cm^3*s^2*g^-1

    Homework Statement "The gravitational constant G is 6.67*10^-11 m^3*s^-2*kg^-1. What is G in units of cm^3*s^2*g^-1 Homework Equations 1kg = 1000g 1m = 100cm The Attempt at a Solution I don't understand how the dimension can change from [L^3,T^-2,M^-1] to [L^3,T^2,M^-1]...
  41. P

    Unit Joule is the unit of work and of kynetic energy

    Homework Statement That is what I learnt, and that it is expressed in Newton*meter. Then I learned that G is equal to 6.47 x 10^ -11 joules and that h is equal to 6.6262 x 10^ -34 joules x sec (N*m*s)and that one photon of light (say red) is equal to 4x 10^ 14 Hz(frequency) and its...
  42. S

    Unit problem in differential equation

    I have one differential equation like dN/dt=c*(other terms with no unit) unit of c is 1/ns. Now if I solve this equation, I will get value of N corresponding to t. (1) Then what will be the unit of t? (2) and if I calculate dN/dt1=(other terms with no unit). where t1=t/c. Then what...
  43. Y

    Is H(hbar)/2c^2 a Possible Fundamental Unit of Mass?

    I have always been critical of the idea of Planck units. They seem to be something conjured from numerology - particularly in view of the fact that it is possible to arrive at diffeent values of the so called fundamental dimension(s) by combiing different constants. But I recently had reason...
  44. W

    Finding unit tangent and unit normal vectors

    Homework Statement The graph shows the vector-valued function r(t). It is given that r(1) = <-1,1> and r'(1) = <1,2>. Find the unit tangent vector T(1) and unit normal vector N(1). (the graph given is that of y = x^2 shifted 2 units left.) Homework Equations (1) T(t) =...
  45. M

    Which is Largest Unit of Heat Energy: Calorie, Btu, Joule, Kilojoule

    Largest Unit of Heat Energy? Which of the following is the largest unit of heat energy: (a) calorie, (b) Btu, (c) joule, or (d) kilojoule. I narrowed it down to kilojoule or btu. I think it is btu.
  46. A

    Anaerobic digester size with chp unit

    Hi I was wondering what the method/theory is behind selecting the size of an anaerobic digester in order to fuel a 500kW cogeneration unit? Any ideas? Thanks
  47. S

    Parametrizing a Hyperbola to Find Unit Tangent & Normal Vectors

    Consider the hyperbola y^2-x^2=1 (y>0) a.) Find a parameterization for the curve and write it in vector form, R(t) (b) Calculate the unit tangent vector as a function of the parameter. (c) Calculate the unit normal vector and the curvature vector as a function of the parameter.
  48. B

    Unit Conversion: How to Find Volts/kRPM for Motor Modeling with 245 RPM/Kv Value

    For a motor modeling project I am trying to find a value that is measured in Volts/kRPM (Voltage constant) , in the motor specs that I am given i have a value in RPM/Kv, If the value for RPM/Kv given is 245, how can i find Volts/KRPM, or is that even possible Thanks!
  49. M

    Calculate point in ellipse given a unit vector

    Hi to everyone. I'm detecting collision between two ellipses. I've got my unit vector, my ellipse center and radius (horizontal and vertical). I want to calculate the point that lies in the ellipse on the direction of the unit vector. See the image attached. Suppose the red arrow is my unit...
  50. B

    Is a 1968 Alternator Guage unit rebuildable?

    The 1968 alternator gauge is 'smoked' The replacement Stewart-Warner gauge is different - it reads "Amperes" instead of "Alternator". I would like to save the casing on my unit...There is a detent on the rim of the casing and looks to me like the main cap would "pop-off", like a watch case. If...
Back
Top