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
  1. S

    Unit Conversion of CO Concentration in Basement to Micro-gram/m^3

    Homework Statement The air near a water heater in the basement of an old home is measured for carbon monoxide (CO) and found to contain 0.1% by volume CO at 22*C and 1 atm. Express the CO concentration in the basement in micro-gram/m^3 . Homework Equations PV=nRT P = absolute pressure (atm); V...
  2. W

    Unit Vector Perp. to a: Solving Problem

    Homework Statement if a =3i-4j find a unit vector perpendicular a Homework Equations Vector The Attempt at a Solution <a> = <3 , -4> <n> = <x, y> : x² + y² = 1 <a>•<n> = 3x-4y = 0 y = (3/4)x x² + (9/16)x² = 1 25x² = 16 x = -4/5, 4/5 y = -3/5, 3/5 There are two unit vectors normal...
  3. J

    Energy unit to kelvin, seconds, density, length

    Homework Statement Convert 1 ##Gev## to Kelvin, and convert ##GeV^{-1}## to meters, seconds, and convert ##GeV^4## to density ##(kg/ m^3).## Homework Equations natural units ##c=h=k_B=1## The Attempt at a Solution I know to convert energy to meters, I can use ##\lambda =hc/E##, I get the...
  4. goonking

    Intersecting Line & Unit Sphere: Find Point of Intersection

    Homework Statement Does the line through the points (−1, −1, −2) and (1, 2, 1) intersect the unit sphere? If so, find the point(s) of intersection. Homework EquationsThe Attempt at a Solution do i also use r = r0 + vt but instead , use equation of sphere this time? so it would be: v=<2,3,3>...
  5. L

    Time-shifted Integral with Unit Impulse Function

    Homework Statement Evaluate the integral. \int_{-\infty}^\infty f(2 -t) \delta(3 -t) \, dt Homework Equations The Unit Impulse function is defined \hspace{18mm} \delta(0) = 0 \hspace{10mm} t \neq 0 \hspace{-15mm} \int_{-\infty}^\infty \delta(t) \, dt = 1 The Attempt at a Solution Using...
  6. X

    Unit vectors for multiple particles? (Quantum Mechanics)

    It's been a little bit since I have studied multi-particle quantum mechanics and I am a little rusty on the notation. Let's say I have a wave function, that consists of the tensor product of two spaces, one for each particle moving, ##|\psi_1,\psi_2>##. Each of these particles is moving in a...
  7. A

    I feel like such an idiot (Help please with unit conversions)

    Homework Statement How am I supposed to know my unit conversions? like for example 1 pound is equal to 453.592 grams I don't know how people do it, it's like they have it all memorized in their head I can't think of a way for me to be able to memorize any of it or know it am I supposed to do...
  8. auditt241

    Unit Tangent Vector in a Scalar Field

    Hello, I am attempting to calculate unit normal and tangent vectors for a scalar field I have, Φ(x,y). For my unit normal, I simply used: \hat{n}=\frac{\nabla \phi}{|\nabla \phi|} However, I'm struggling with using this approach to calculate the unit tangent. I need to express it in terms of the...
  9. J

    Energy per unit time of a wave

    Homework Statement Is intensity related to this question? The answer is B. Homework Equations I^2 ∝ A^2 I=P/A, where I is intensity, P is power, and A is area The Attempt at a Solution I tried using I=P/A, and after substituting, I get, A^2=E/S, which gives E=A^2 S And then, the new wave...
  10. Y

    Calculate Board Feet from Log Diameter and Length | Basic Unit Conversions

    Homework Statement Calculate the approximate number of board feet (one board foot is defined as a volume of ##1 in \times 1 ft \times1 ft## of lumber that would be available in a log that has a diameter of ##34 cm## and a length of ##3 m##. Assume the log is a right cylinder and that the saw...
  11. O

    Unit conversion - stress-wave propagation speed

    Dear Friends, The stress-wave propagation speed is calculated using : sqrt (elastic modulus/density) The unit of elastic modulus is GPa, and that of density is gram/cm^dim Can anyone please tell me how I can convert the resulting value to m/s (meter/second)? Regards
  12. E

    Engineering Want a BME 1st sem book (S.I. unit)

    I'm a mechanical engineering student 1st yr . I need suggestions regarding books for basic mechanical engineering and engineering mechanics . A book with basics n proper language.
  13. G

    Capacitance per length unit of coaxial cable

    Homework Statement Coaxial cable has double layered dielectric. a=2mm, b=4mm, c=8mm, εr1=3, εr2=4.5, Uab=1000V 1. Calculate capacitance per unit length of a cable. 2. Calculate inner and outer charge densities of a cable. 2. Homework Equations Gauss law C'=Q'/U σ = nD σp = nP 3. The Attempt...
  14. G

    Capacitance per unit length - two cylindrical conductors

    Homework Statement Two cylindrical conductors, of distance between them d and radius a (a<<d), have dielectric layer of relative permitivitty εr and thickness a. Calculate capacitance per unit length of this system. Homework Equations Capacitance per unit length, C'=Q'/U Gauss law, cylindrical...
  15. R

    What is the unit of force in SiC structural optimization?

    I'm reading a paper on a simulation of graphene and carbon nanotube growth on SiC, in the paper they give a few computational details about the structural optimization of the SiC model using a conjugate gradient method and they state the maximal force component as 1x10^{-4}Ha/a_o What is this...
  16. PhotonSSBM

    Perpendicular Unit Vectors in the x-y Plane: Is My Solution Correct?

    Homework Statement From Kleppner and Kolenkow Chapter 1 (Just checking to see if I'm right) Given vector A=<3, 4, -4> a) Find a unit vector B that lies in the x-y plane and is perpendicular to A. b) Find a unit vector C that is perpendicular to both A and B. c)Show that A is perpendicular to...
  17. Stephanus

    Unit of Acceleration: Calculating Speed with Velocity Addition Formula

    Dear PF Forum, I have a problem concerning the unit of acceleration. All this time in Relativity, we have been talking about c. Either as a distance unit (light travel for 1 second) or as speed. Sometimes we describe it as 300,000. Sometimes as 300,000,000 or 186,000. The time unit is always...
  18. JR Sauerland

    Is there something I'm missing about this unit circle thing...?

    I get the dynamics of what the question is asking. What I don't get is how to know what pi/8 is. What I've been doing this entire time is plugging it into the calculator as a fraction, and getting the decimal value of it and comparing it to other values I know. I know that pi radians = 180...
  19. T

    Rate of Acceleration: Find Unit of Change

    if acceleration is defined as rate of change in velocity, then how do you find out the unit of rate of change of acceleration?
  20. L

    Why Are There Different Units for Moment of Inertia?

    Hi, I am a bit confused about the units of MI...I read that MI of rectangle is b*d^3/12,so unit is mm^4..Also i read in wiki that unit of MI is kg.mm^2... Both are correct,but why this difference is?
  21. K

    About wavepacket unit and probability

    Hi all, In quantum mechanics, we consider the squared modulo of a wave function has meaning of probability, so does it mean a wave packet should be unitless? I am reading some materials online about the Gaussian wave packet...
  22. T

    Divergence of radial unit vector field

    Sorry if this was addressed in another thread, but I couldn't find a discussion of it in a preliminary search. If it is discussed elsewhere, I'll appreciate being directed to it. Okay, well here's my question. If I take the divergence of the unit radial vector field, I get the result: \vec...
  23. L

    What is the unit conversion for 28.8 Volts/(Meter/Second)?

    Hi ALL i need to unit Conversion : from: 28.8 Volts/(Meter/Second) to (....) Volts/(Inch/Second) from: 28.8 Volts/(Meter/Second) to (....) milliVolts/(milliMeter/Second) Thanks
  24. L

    What is the significance of j2 in this problem?

    What's j2 in this problem? 1. Homework Statement Homework Equations The Attempt at a Solution a. What's j2 in this problem? b. How did we use the fact that we have a unit impulse? c. What are our first thoughts and strategies when seeing the problem ? What is our strategy? It looks...
  25. S

    Standard unit vector in the positive z direction?

    http://tutorial.math.lamar.edu/Classes/CalcIII/CurlDivergence.aspx In the above link, in the 2nd to last blue box on the page (where it tells how to solve a line integral with respect to a vector field using the curl), it says that the line integral of vector field F with respect to r (with an...
  26. K.Callaghan

    Unit when multiplied or squared

    Homework Statement Consider the following hypothetical question: (5 lbs•m^2) =a (5 rad/s^2) =b If (a) and (b) are each multiplied by 2 what do the units become? Similarly if (a) and (b) are squared what do the units become ?
  27. H

    Why is (not) the resulting unit of this equation rad/s ?

    Hi guys, My first time here. Looks like a nice forum with friendly members. I have a question. I'm kinda confused by this (and I know it's a shame since I'm on my third year University, almost making my degree). What I remember from my kinematics/dynamics classes this (or similar) equation...
  28. R

    Unit Vectors for Polarization and Wave Vector Directions

    Homework Statement I am having difficulty understanding the very first step of the following solved problem (I understand the rest of the solution). How did they obtain the expressions for ##\hat{n}## (the direction of polarization), and ##\hat{k}## (the unit vector pointing in the direction...
  29. kareeemmuhammed

    Time Unit Vector: Calculate d'Alembert with 4 Vectors

    Hello every one i have question what is the unit vector of time component like c^2 t^2 -x^2-y^2-z^2 = 0 OR if we need to calculate the d'alembert cross some 4 vector have 3 space component x y z and unit vector i j k and ct component what is the unit vector in Ct direction ?
  30. J

    Simple atomic unit conversion check

    Hi I'm converting some numbers to atomic units, and it's important that I get it right. Would be happy if someone could reassure me. I want to convert the units of an electric field measured in kV/cm to atomic units. Here is what I got: \frac{kV}{cm}=\frac{10^3}{10^{-2}}\frac{J}{C\cdot...
  31. marcus

    Introducing the Model T time unit "Lizzie": key to H_infinity

    The Ford Model T, affectionately known as the Tin Lizzie, is thought to have been the first widely affordable/accessible automobile. Production of the Model T started in 1908. I'm looking for a cosmo-friendly time unit that is short enough to be real and familiar to all of us, but at least an...
  32. M

    Area of figure, resulting from unit square transformation

    1- Let the linear operator on R^2 have the following matrix:A = 1 0 -1 3 What is the area of the figure that results from applying this transformation to the unit square? 2- I am abit confused here, I thought that the matrix for the unit square would be, 0 0 1 0 0 1 1 1... But...
  33. D

    Radians and the unit of rotational energy

    Hello everyone I have a question regarding radians and the unit of rotational energy (which has been probably asked several times elsewhere but is still confusing for me :-) ). As I understand radian (rad) is a UNIT that is dimensionless (thus cannot be omitted), correct ? Now if I want to...
  34. wolfspirit

    Find a unit normal to the plane containing a and b

    Homework Statement Find a unit normal to the plane containing a and b. a=(3;-1; 2) and b=(1; 3;-2) Homework Equations \frac{V}{|V|} where V = a+b The Attempt at a Solution (3;-1; 2) +1; 3;-2)=(4,2,0)=V |V| = \sqrt{4^2+2^} = 2\sqrt{5} there fore the unit vector is (\frac{2}{\sqrt{5}}...
  35. R

    Unit Error in Oppenheimer-Snyder 1939 Paper?

    Is there an error, perhaps typographical, in the famous 1939 Oppenheimer-Snyder paper "On Continued Gravitational Contraction" (Phys Rev v56 Sept 1, 1956 pp 455-459)? Do the units balance in equation 37? The last term inside the last parantheses ##\frac{3r_0^{1/2} \tau}{2R_b^2}## where...
  36. C

    Find Unit Vectors for f(x,y) w/ D_uf=0

    Homework Statement For f(x,y)=x^2-xy+y^2 and the vector u=i+j. ii)Find two unit vectors such D_vf=0 Homework Equations N/A. The Attempt at a Solution Not sure if relevant but the previous questions were asking for the unit vector u - which I got \hat{u}=\frac{1}{\sqrt{2}}(i+j) for the maximum...
  37. V

    Converting a unit vector from cartesian to cylindrical

    Hi, I was wondering if anyone could help with a vector question that I have. If I have a unit vector defined in cartesian co-ordinates as p= (0,1,0) how would I go about converting this vector to a cylindrical geometry. I understand that I will probably need to use p_r=sqrt(px^2+py^2) and...
  38. P

    Finding constant acceleration, unit difficulty

    Homework Statement An Indy 500 race car's velocity increases from 4m/s to 36m/s over a 4 second time interval. What is its acceleration? 4m/s is the initial velocity, 36 m/s is the final velocity, and time is 4 seconds. Homework Equations final velocity = initial velocity + (acceleration x...
  39. B

    Understanding Flux: Does it Have a Unit?

    Flux is the no. Of electric field lines per unit area..how can it have a unit
  40. at94official

    Converting 1,602 ×10^−19 C to SI Unit Prefixes

    Just simple questions and I need clarifications why is that your answer please. 1,602 ×10^−19 C write to SI Unit Prefixes
  41. A

    Wire Attracts Loop - Electromagnetic Unit

    Homework Statement A rectangular loop of wire is placed next to a straight wire, as shown above. There is a current I in both the straight wire and the loop. The dimensions shown in the figure are a, b = 2.2a, and c = 8a. What is the magnitude of the force on the loop? Express your answer in...
  42. Hardik Batra

    What is the unit value of coulomb constant(k)?

    What is the unit value of coulomb constant(k)? I just want to know the CGS unit value of k. In my book it is said the CGS unit value of k is 1. By i don't know how it come.?
  43. J

    Laplace Transform question with unit step function

    Homework Statement Homework Equations Laplace Trasformations The Attempt at a Solution a. done b. f(t)= t -3*t*u(t-1) + 4*u(t-1) -3*u(t-2) -2*t*(t-2) c. 1/(s^2) - (3e^-s -2e^-2s)/(s^3) + (4e^-s -3e^-2s)/s d. 1/(s-1) * (1/(s^2) - (3e^-s -2e^-2s)/(s^3) + (4e^-s -3e^-2s)/s) These are the...
  44. R

    Unit circle derived distribution

    Hi Assume an x-coordinate from the unit circle is picked from a uniform distribution. This is the outcome of the random variable X with probability density function Xden(x) = 0.5 (-1 < x < 1). The random variable Y is related to the random variable X by Y = f(X) = √(1-X2) and X = g(Y) =...
  45. F

    Calculating Bohr Magneton: Need Help with Unit Conversion

    Hi everybody; I am triying to calculate the Bohr Magneton (eħ/2mc); I am suposed to express it in units of MeV/ Gauss, but I have not idea how to transform charge/time, which is what I obtain when I introduce the units in the formula. Can anyone help plase? Thanks.
  46. J

    Solar updraft tower: How small a working unit can be made?

    solar updraft tower: How small a working unit can be made? My reason to ask this question is: I think that if a commercial unit is ever to be built, first the concept must be widely established. One or two working examples of a size similar to the prototype built in Spain won't likely prove...
  47. E

    Exploring Challenging Questions in Grade 11 Nuclear Physics Curriculum

    Hey guys, wasn't too sure where I should post this but here goes: Im currently taking a grade 11 introductory physics course in Ontario, Canada. We are currently learning the basics of nuclear physics. For most units, I'm able to foresee the thinking (hard) questions our teachers usually point...
  48. Rajkovic

    Does the Planck Unit of Time Support Julian Barbour's Theory on the End of Time?

    I'm reading Julian Barbour the end of time..I don't know if It's a good reading.. According to Planck unit of time (5.39121 × 10^−44 seconds), could the universe be said to have a "frame rate" and "snapshots" (as Julian Barbour mentions) could exist? (and, incidentally, Zeno's arrow paradox...
  49. A

    Calculating Per Unit Fault Impedance: Finding Errors in Given Relationships

    Homework Statement Given the relationships: Xpu = MVAbase / MVAfault Xpu = ( MVAbase / MVArated ) * ( X% / 100 ) MVAfault = sqrt(3) * V * Ifault Xohms = [ V / sqrt(3) ] * Ifault Homework Equations Show that: Xpu = [ MVAbase / V^2 ] * Xohms The Attempt at a Solution No matter how I...
Back
Top