Unit Definition and 1000 Threads

Special Unit 2 is out on Amazon, finally, not bootleg.

Can someone clarify this for me. Is it the case that Planck scale unit is the smallest unit of measurement that can can observe/make, but not the smallest unit of measurement that exists? If so, is there some name for that which is smaller? Is there some fundamental measuring unit that...

Hi, I want to understand the meaning of unit impulse response when time flows. An example is given below: In the example the left signal depicts a δ[n] function value of which is 1 only at n=0. The LHS signal is response of the system to the unit impulse. I want to understand how to...

Hello! I was reading an article from Wikipedia(https://en.wikipedia.org/wiki/Lapse_rate) and the formula seems to me not homogenous since g is in m/s2 and cp in J/K=(kg*m2)/(K*s2) so at the end, we'll get K/(kg*m). How they get rid of kg-1 ? Thanks

Does anyone know of a general expression for the unit dyadic, given in terms of the language of general curvilinear coordinate systems?Perhaps an expression for its components?Perhaps an expression, just appropriate for use with orthogonal coordinate systems?$$~$$ In cartesian coordinates the...

As you may know, below is the conversion process of square unit cell into circular shape in order to calculate the thermal utilization factor (f) for a lattice. As far as I know, it is really difficult to make a simulation for which a lattice is constructed as a circular fuel and square...

in question 10.19 , i use equation 10.26 to do the question . I have all the values of all variables , except q ( load per unit area) ... Homework EquationsThe Attempt at a Solution How to get q ? It's not stated in the textbook . Is there something to do with the homework =4m ?? I assume q =...

I am computing force between two magnetic poles each of one unit pole (in emu) and situated one centimeter apart. In electromagnetic units: ##F_{dyne}=\dfrac{p^2}{r_{cm}^2}=\dfrac{1^2}{1^2}=1 dyne## where ##p## is pole strength in emu In SI units: ##F_{N}=k_A \dfrac{P^2}{r_m^2}=10^{-7}...

Homework Statement I'm having trouble understanding how to find the angle of a vector. Here we are given the x and y component to help us find the direction of vector C. In this case, both x and y component is negative, so it should be in the third quadrant. I know that since we have both the x...

How do I express ex,ey,ez in terms er,eθ,eZ? r=(x^2+y^2)^1/2,θ=arctan(y/x),Z=z A(r,θ,z) ∂A/∂x=x/(x^2+y^2)^1/2er+(-y)/(x^2+y^2)eθ=cosθer-(sinθ/r)eθ ex=(∂A/∂x)/|∂A/∂x| I should get ex as cosθer-sinθeθ, but I don't get ex correctly. am i doing this wrong?

Homework Statement Given Thrust-specific fuel consumption cT=0.5279lb/lbf*h... as other units in the question are in SI unit, I have to convert it to (N/s)/N first... Homework Equations 1 lbf = 4.448 N 1 lbm = 0.4536 kg Thrust-specific fuel consumption = weight of fuel burned per unit time...

I have RMU training from tomorrow. The RMU will be of 24kV Siemens make. I have no idea about it. I would like to get prepared for training. Can you tell me about it in detail with Single Line Diagram.

Hello, I am struggling a little bit with what I believe to be a simple unit conversion. For this problem, I have many fluxes given in units of Janskys. I would like to convert them from their original units of Jy = 10-23 erg s-1 cm-2 Hz-1 to units of erg s-1 cm-2 Angstrom-1 When I try to do...

That is, an honorific title. Eg force is cited in Newtons, charge in Coulombs, etc, as opposed to kilograms.. Generically "m" seems to be used as a symbol I guess but it overlaps with generic references to mass. eg F = ma is usually taken as referring to mass per se not inertia. But it...

Edit: thread moved from non HW forum. I'm trying to calculate the unit molecular weight of polystyrene. I'm given the structure, and I have to count all the elements in the structure. To calculate the weight, I keep counting 8C & 7H. The correct answer is 8C +8H. I'm having a hard time...

Let $S_n$ be the sum of lengths of all the sides and all the diagonals of a regular $n$-gon inscribed in a unit circle. (a). Find $S_n$. (b). Find $$\lim_{{n}\to{\infty}}\frac{S_n}{n^2}$$

hi, in perovskite crystal, such as BaTiO3, due to the off-centre of Ti ion, there exists a polarization moment in the unit cell (as shown in below link). my question is: does the disposition of Ti atom lead to separation of electron cloud from the nuclei of the Ti atom and so the Ti atom plays...

hi, i am designing a fuzzy logic controller, i need to use a delay block for the change in error signal now i don't know that based on what factors should i choose the sampling time for this unit

Hi. I'm trying to self-study vector calculus and I have to admit I struggle with it. As regards finding normals to a surface I know 2 ways - one involves writing the surface equation as f(x.y.z) = 0 and taking the gradient. The other method involves writing the surface in terms of 2 parameters...

I've been told that ##[0, 2 \pi )## is not homeomorphic to the unit circle in ##\mathbb{R}^2##. Why not? From intuition, it would seem that I could just bend the line segment to fit the shape of a circle.

Where is my simplification wrong?

I haven't read any of the X-Men books.. what units do they use for the powers? For example.. if a telekinetic can stop or deflect a meteor like in Tunguska in 1908.. what unit should be used for comparison purposes.. can Jean Grey also deflect an meteor?

what is this unit, ⊕ ?? was reading an astrophysics book and came across it. "Gas Giant planets (>10 M⊕)" I am guessing that its mega something?

What is definition of heat? And why it's unit is kgm^2/s^2? I couldn't be able to link the unit to the definition.

Homework Statement Homework Equations The equation has already been given in the question. The Attempt at a Solution So what I did was find r'(t), r"(t), v(t), v'(t) and plug it into the equation. I've done 3 different full pages of this and have gotten 3 different answers. I'm guessing due...

Why is the quantity "information" missing from the SI system? Also, if they did add it, do you think it would be added as a base unit or dimensionless derived unit?

What is actually the unit normal vector of a surface? Is it this? Or this one? I see that those are opposite in direction. But, I want the correct one, which means that it should point outward. So, which one is correct?

What unit would i end up with if i divide 1 Joules/kg by .5 meters? Would it be N/kg?

Hi guys, so I am building this light fixture as a concept an inside of the light fixture is a sealed cavity which houses the power supply and control gear. Now to service this unit that cavity opens up, but let's say on a hot humid day the unit is opened and that air enters the cavity. Its then...

I have a central heat and air unit enclosed in a closet like area and it is very loud in my living room, is there a way to install a noise cancelling unit to muffle that sound of the blower unit?

I can't find equations for wall thickness or required temperature to generate steam at 6000psi. The goal here is a pressure vessel 'cylinder' 30" diameter, 36" long. It will be used to pump 42000psi hydraulics using a piston pump directly driven to a smaller series of pistons to allow the...

The unit of angular momentum is kg * m^2 / s (or I * W). The moment of inertia for a point mass, mr^2's unit is kgm^2. That means the unit of W has to be 1/s. I'm having trouble converting this to radian/s. Thank you!

Hi everyone. I was looking at complex numbers, eulers formula and the unit circle in the complex plane. Unfortunately I can't figure out what the unit circle is used for. As far as I have understood: All complex numbers with an absolut value of 1 are lying on the circle. But what about...

Homework Statement let's use this symbol to denote the unit impulse function δ When integrating the unit impulse function (from negative infinity to infinity) ∫δ(t) dt I know that this results in a value of 1 and is only nonzero at the point t = 0. However for example take this integral into...

Actually that's very easy question but I have some difficult to understand the logic behind . So-"The initial velocity of an object (m/s) is Vi=1i+5j+2k. And the final velocity is Vf=3i+5j+7k. What was the change in speed of the object?"X Solution - |Vf|-|Vi| = √(32+52+72)-√(12+52+22) = 3.63...

Homework Statement The equation of state of an ideal gas is p = nkT, where p is the thermodynamic pressure and n = N / V is the thermodynamic variable for the number of particles per unit volume. The n dependence of the free energy f per unit volume of the ideal gas is obtained by the following...

I have been in my physics crash course for my entrance exam. I was looking at the chapter "Units and Measurement". I got a doubt in this chapter and I didn't get it cleared by my teacher. So I am posting this in this forum. We have 7 fundamental quantities and other quantities are derived...

(cos(s), sin(s)) gives an arc-length parameterization of the unit circle so that the speed is constantly 1, but the second derivative doesn't give zero acceleration which should be the case with constant speed?

Why is there a need to find unit vector? If we are given a vector we can always find its direction.

Hi When I was writting my thesis I found in an article, published in International Journal of Heat and Mass Transfer, an unit of mass flow rate G - kg/(m^2*s). Isn´t it wrong? I think that the unit of mass flow rate is kg/s. Would you mind helping me to figure it out? Thanks.

I'm trying to deduce the weight of 1 atomic mass unit (##1u##) in ##kilograms## from the following scenario: One atomic mass unit is 1/12 of the weight of a ##^{12}C## atom in its ground state. A ##^{12}C## atom consists of 6 protons, 6 neutrons and 6 electrons. This means that $$1u =...

Homework Statement Quantities without unit of measure are: A) Necessarily scalar B) Necessarily vector C) Can be scalar or vector D) They are neither scalar nor vector Justify your answer!Homework Equations No equations The Attempt at a Solution For example, the refractive index of a medium...

Here is my transfer function, G(s) = 1/(s+1). I know this will be a half parabola looking output with a unit step input whose initial value will be 0 and final value will be 1. I got the initial value by takeing the limit of the function at inf and the final value by taking the limit of the...

I'm having trouble even beginning to figure out how to approach solutions for this. I begin with a unit cube, and imagine all the possible lines that intersect the cube. I am assuming there must be an average length of these intersections; I want to find that average length. Another way to...

Homework Statement Suppose a harp string is tuned to middle C (C4) and is 0.56m long. If I want the tension to be 193.5 N, what mass per unit length do I need the harp string to be? Calculate your answer in kg.m Homework Equations Vs = sqrt(T/μ) V = fλ The Attempt at a Solution Having a very...

Homework Statement Find the unit vector perpendicular to the level curve of f(x,y) = x2y-10xy-9y2 at (2,-1) Homework Equations Gradient The Attempt at a Solution I'm not sure what it's asking. Wouldn't this just be the gradient of f(x,y) evaluated at (2,-1) then normalized? or am I missing...

I have been thinking around the definition of a unit in a ring and trying to fully understand why the definition is the way it is ... ... Marlow Anderson and Todd Feil, in their book "A First Course in Abstract Algebra: Rings, Groups and Fields (Second Edition), introduce units in a ring with 1...

I have been thinking around the definition of a unit in a ring and trying to fully understand why the definition is the way it is ... ... Marlow Anderson and Todd Feil, in their book "A First Course in Abstract Algebra: Rings, Groups and Fields (Second Edition), introduce units in a ring with 1...

Homework Statement Given ## d \vec r = dr \hat r + r d \theta \hat {\theta} + r \sin \theta d \phi \hat {\phi}.## Find ## d \hat r , d \hat {\theta} , d \hat {\phi}. ## Homework Equations I know that ## d \hat {e_j} = \omega^i_j \hat {e_i} ## and that ## \omega_{ij}=- \omega_{ji} ## and ## 0 =...

Can anyone explain to me how it comes that US not have accepted the use of SI ? Do you not understand the benefits ? Would it not be more effective if the new generation of students could concentrate on understanding fundamental physics relations rather than struggle whith old-fashioned and...