Units Definition and 976 Threads

M(t) = M0 + n (t - t0) where M(t) = the Mean Anomaly at time t; M0 = the Mean Anomaly at the Epoch time; n = (G*(Me+Msat)/a^2)^.5 = the satellite orbit's Mean Motion; t = the chosen prediction time; and t0 = the Epoch time. My question is...

Hello, I have a magnetic field in [MMaxwells*N] (Megamaxwells per turn) and I need to convert it into Gauss. I'm not sure how to. Help would be appreciated.

Homework Statement I need to find the diameter of an object in the sky, which i did, but not sure about the arc second. I convert it into degrees wondering how i would remove the degrees. Homework Equations d=2Dtan(a/2) The Attempt at a Solution where D is distance a is angular...

Just calculated the Tangential speed that music is detected from a CD. I found it using Vt=r\omega where r was in meters and \omega I converted from revolutions per second to radians per second. What unit of measure is tangential speed in? Thanks, Leah

excuse me. How converts Bq/cu.cm to Bq/L? tnk.

My teacher recently docked me 6% on a test because I failed to put units on two values that ended up being zero. For as long as I can remember an answer that is zero does not need units. I looked up examples in our textbook and they left units off answers with values of zero as well. I was...

Hi, Hopefully this should be a simple and quick question. I've seen many calculations done with \hbar = 1. If I want to convert back into physical units, what is the corresponding transformation? I know wiki gives a description of...

I do not want to post the entire homework problem as I understand all of it except this one part. The problem deals with energy balance and it states that water is flowing through a nozzle. (From a bigger cross sectional area to a smaller one.) I am trying to calculate the energy of the...

I have a question that sounds easy but as of yet no one has been able to give me a satisfactory explanation. I made a plot of mobility (cm^2/Vs) against temperature (K), i then wanted to find an expression that showed the relationship between the two. What i did was took the natural logarithm of...

this problem might be extremely simple but the wording is confusing me b]1. Homework Statement [/b] "What dose that force correspond to in equivalent acceleration in g uints? (9.81 Nt/Kg)" the force i had from the question be fore is 1.8uN (micro) soooo is it asking me how many g's...

Hi! I am new to these, and off the bat am confused by the units. Manufacturers quote resolution either in units of length, e.g. 0.04 nm, or HZ. For example, 0.04 pm / 5MHz 0.16 pm / 20 MHz 0.8 pm / 100 MHz. I am thrown by this since I thought frequency was the inverse of...

So, we learned that the units of Moment of Inertia are mm^4. My question is how do they use moment of inertia in static calculation (where we use Newtons), if Moment of Inertia is in mm^4?

Greetings, Is space made up of individual units like pixels on a computer screen? And the amount of space in the universe is increasing? If so, I'm curious how to calculate how often a new pixel comes into existence between any two existing pixels? Or if a new pixel comes into existence every...

Homework Statement Determine the nilpotent, idempotents and units in a) F[x]/<x2-x> b) F[x]/<x2> Homework Equations The Attempt at a Solution How do I do this without a specified Field? For a) the elements in R would be {a+bx: a,b are in F; x2=x} b) {a+bx: a,b in F; x2...

Hi, I know nearly nothing about physics, I'm a mathematician working on a computer program. Anyway, I have to write a program and my boss suggested that I use atomic units and that at the end of the program I can "scale up" to natural units if desired. I tried to read up on these units, but...

Homework Statement In the equation ΔT = Pθ, P is power in Joules per second and ΔT is the temperature difference in °C. Use dimensional analysis to find the unit of θ. Hint, Joules has units of Force time distance. My question is: I don't understand what they mean by finding the unit of θ. Are...

Homework Statement find the units for this equation: ML^-2T^-1 Homework Equations The Attempt at a Solution We were given the answer as kg m^2/s^3, but I just cannot figure out how to arrive at that. I thought the answer was kg/m^2s

Putting together a spreadsheet to calculate the hydrogen spectrum, cannot seem to get the right mix of units to get the Rydberg constant of 13.605... eV also, what is the significance of R (1/n^2-1) converging to R as n gets large? can anyone put this together or refer me to a source that...

Find all units in Z12 X Z6 and their inverses. What i did was find the units of Z12 which are 1,11,5,7 then the ones of Z6 which are 1,5 and take the cartesian product of those two sets?

In lab for our final project, we used a Wide Range Strain Indicator connected to strain gages on a part we machined to function as a scale. The Indicator device was much like this one: http://www.datasheetcatalog.org/datasheet/vishay/3800.pdf What units would the numbers be that we're...

Moment is Newtons per meter, and work is Newtons per meter. I'm confused as to how to relate them. Are they essentially the same thing?

Homework Statement So the question is I have to use some trial function of the form \sum c_if_i to approximate the energy of hydrogen atom where f_i=e^{-ar} for some number a (positive real number). Note that r is in atomic unit. Homework Equations Because r is in atomic unit, I think I should...

I know that the mass of subatomic particles is usually given in electronvolts, and that c^{2} is set to 1 so that we can say, "This particle has a mass of 13 eV." However, if you divide 13 eV by c^{2}, you get an answer, x. What units is this in? Oh, also, what units do we use c in in the...

Homework Statement 1) What are the units for the charge, Q? 2) What are the units for ke*Q? 3) What are the units for - ke*Q / R, R=radius (m) 4) What are the units for 2*ke*\lambda*ln R 5) What are the units for - 2*ke*\lambda 2. The attempt at a solution 1) C, Coulomb's 2) N*m2/C...

Homework Statement In manipulating transmission spectrum data from GaAs and InP I'm told to "Look up the refractive indices of GaAs and InP in the region of  = 1.0 micron, and use these to correct your experimental data for reflective losses and plot the corrected transmission T’ in...

what is meant by density, such as the baryonic matter density in cosmology, in "units of the critical density"? its mentioned in a question i need to do but i don't really know what it means.

How many cubic meters are in 5.43 x 10^6 cm^3? There are .001 meters in the centimeter. m= meter cm= centimeter This is what I did: 5.43 x 10^6 cm^3 (.01m/1 cm)^3 And then did the calculations, which gave me: .0000043 x 10^6 m^3 or 4.3 m^3. Not sure if I set up the...

The units on Plank's constant is m^2 * kg / s I'm new to all of this stuff so... Why?

Homework Statement A pressure of 3000atm is measured with a dead-weight gauge. The piston diameter is 0.17in. What is the mass in pound-mass (lbm)?Homework Equations 1) P=F/A 2) F=PA 3) F=mg 4) F/g=mThe Attempt at a Solution I first used the given diameter to find the cross-sectional area of...

Are the units for effective mass in kg? I have been trying to wrap my head around the concept then realized I wasn't even sure about the units. The formula is: m* = (h/2pi)2(d2E/dk2)-1 the units of h are in J-s, and the units of E are in J so... (J-s)2/J = J-s2 J = kg m2/s2 kg m2 s2/s2...

Homework Statement A thermometer has its lower and upper fixed points marked as 10 and 80. When it reads 40, what is the corresponding temperature on Centrigrade scale? The Attempt at a Solution I have no idea of solving such type of questions.

I would like to understand how units of distance, time and mass are defined on the golden record on Voyager spacecraft . I suppose the units are similar to natural units (speed of light=Planck constant=1), except that the basic unit is not GeV: The unit of energy is the energy...

Homework Statement Define the set of units in R[x] where R is a commutative Ring and R[x] the polynomial ring.Homework Equations Unit: X is a unit in R if there exist a Y in R such that XY=1The Attempt at a Solution At first I thought it was this: R[x]* = {u +a1x + a2x^2...anx^n : u2=1 and ak2...

Homework Statement Find the units, nilpotents and idempotents for the ring R = [\Re \Re] [0 \Re] (Those fancy R's are suppose to be the set of Reals by the way.. not good with this typing math stuff) Homework Equations The Attempt at a Solution I'm not actually sure I...

Homework Statement Is there any standard method known to work with units in which speed of light (c), Planck's constant (h), Boltzmann constant (kb) are given by: c=1 h=2*pi (i.e. h_cross=1) kb=1 For example, how can we calculate Newton's Gravitational Constant (G) in these units. If...

Is there good list of common units (good as in including the unit, symbol, and quantity it measures) anywhere out there? I did some searching and came up with this, but I'm unsure how good it is as a source. http://www.alcyone.com/max/reference/physics/units.html Any supplementary list or...

I couldn't decide whether to place this in the Physics or the Math section of the forums, deep down it is really a Math question for Physics problems. So mods please move if you feel it would be more appropriate in the Physics section. So when doing calculations, I always like to make sure my...

I have the equation for heat capacity for constant volume and pressure. Cv = Cp -R So for Cp I have the units J/k and for R the units are J/k mol. So my question is related to that mol. Is it right that I need to get rid of that mol? if so how? Does it involve Avogadro's Constant? Or do...

mechanical (work) unit is J/kgK Heat unit is kcal/kgK what is this mechanical (work) unit, Heat unit ? I'm not able to understand it. please elaborate

Hi folks, I've never taken a real quantum physics course, so this question miiight be really silly, but here it is: I'm wondering if there's any research going on or any established theories about time and space themselves occurring in quantum units rather than occurring in a continuum that can...

Pressure differentials in Double Glazing Units Hi I hope I'm in the right place. I'm also hoping that this problem will appeal to someone! I'm a joiner and I make windows. I am in a discussion on a woodworking forum about the physics of a double glazed unit and it's starting to go above...

Homework Statement trying to show that the units W m-2 are equivalent to kg s-3 Homework Equations 1 W = 1 J s-1 ? The Attempt at a Solution energy per unit time? p.s. I am very new to physics, a beginner in understanding the whole concept of units, any advice?

I'm having a hard time visualising how the units of torque are measured. I can picture how quick m/s or RPM is. But when it comes to torque, I cannot picture what 'x' amount of N/m does. Example, for a motor with 3.3 Lb-Inch or 7N/cm. Does it move 3.3lb of weight per inch? Does that mean...

Homework Statement A problem about pressure vs. temperature of a gas. Details not necessary since I'm just looking for specific help (see "Relevant equations"). Homework Equations P = 0.0034T + 0.9517 This is the equation that I'm given, which is the slope of the line plotting pressure vs...

I see that the diffusion coefficient (of diffusivity) D has units of something like cm^2 / s. I'm having trouble understanding what those units mean. For example, speed has such units because something travels a certain LENGTH in a certain TIME. Could someone explain this for me? Thank you.

Hi all! I came across 2 questions on my course work, and i don't know what is required here, can some one help please? Q.1 Define the common derived units of the following physical quantities; and express them in terms of the base units: Mass, Length, Time and Electric charge (or Electric...

What are the units of vectors and dual vectors? And where do the the units in the metric need to be placed so that V^{\mu}V_{\mu} is a scalar? Taking charge density and current density that combine as a 4-vector, J^{\mu} \partial_{\mu}, and it's dual vector J_{\mu} dx^{\mu}, which units go...

Hello, Something I've wondered about for some time is what happens to units once we pump them into a exponential or log function. For example in neutron attenuation I(x) = I_0 * exp(-Sigma * x) I feel like this something I should know, but I just don't get it. I suspect what's...

A mass M is at the top of a rotative arm, with a radius R, at a certain speed V. Lets take M=60kg, R=5meters and V=10m/s. We assume the movement generated from some kind of natural source (wind, water..), is permanent and constant, and there is no loss (100% efficiency). How many watt of...

Homework Statement I'm trying to find out the mean motion of Halleys Comet using the equation. n = \sqrt{\frac{GM}{a^3}} where we have taken the mass of Halleys comet to be negligible compared to the sun, M is the mass of the sun and a is the semi major axis. The Attempt at a...