# What is Unit conversion: Definition and 114 Discussions

Conversion of units is the conversion between different units of measurement for the same quantity, typically through multiplicative conversion factors.

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1. ### I Confused about unit conversion involving natural units

Hello! I have an expression whose natural units are Joules, but all the terms are expressed in terms of cm##^{-1}## (it is for an atomic transition). I have a term in the expression whose units are 1/A (angstrom) and I am not sure how to convert it to what I need. On one hand, if I were to go...
2. ### I Unit conversions of Force

Hello. Im studying for an exam and came across this simple unit conversion question but I haven't done something like this in a long time! I understand the conversions of each unit individually but get a bit stuck combining them. This is the question: A force of 100 N is exerted on an object...

Suppose I want to convert 100,000 metric Tonnes to kilograms, then I would perform, a unit cancellation: Given that 1 t = 1000 kg ##100,000 t \times \frac{1000~kg}{1 t} = 1 \times 10^8 kg##, however, why are we allowed to multiply the 100,000 by that? My reasoning is, ##1 t = 1000 kg## ##1 =...
4. ### Unit conversion question

How do you convert ##1.66 \times 10^{-7} s ## to ##ns##? I know the answer is ##166 ns = 160 \times 10^{-9} s## however what is the thought process? Many thanks!
5. ### Highest useful Fahrenheit temperature?

I was watching a video about energy storage, and the subject was stuff that was around 1500° celsius, and for the whole video the graphics kept including Fahrenheit equivalents. Now I use Fahrenheit when checking the weather outside. But that doesn't make 2732F° any more relatable a...
6. ### A Underwater acoustic unit conversion

Hi all I have acoustic noise level value in dB vs 1 dyne/sq cm e.g. -10 db vs 1 dyne / sq cm. I need to convert it into dB ref 1upa unit. How i will convert it? Thanks & Regards
7. ### Useful Cooking Unit Conversion

A hollow rectangular tube with cross-sectional area of 1 barn and a length of 1 megaparsec will hold a quantity of material of approximately 2/3 of a teaspoon.
8. ### Do oxides react react with a weak acid like phosphoric acid?

I have an ash which is a mix of oxides (Cr2O3, CuO, ZnO, PbO, CdO, NiO, SiO2, MgO, CaO). I am adding phosphoric acid. But as a weak acid, will it react with oxides? If so, are these conversions 100% or more of a equillibrium (partial conversion). I you need more information, be sure to ask.
9. ### I Conversion factors derivation.

Queries regarding MKS to CGS system for the following formulas. Force - Newton (MKS), Dynes (CGS) Work - Joule (MKS), Ergs (CGS) 1N = 10^5 dynes. 1J = 10^7 ergs. How the above unit conversion formulas are derived ?
10. ### MATLAB Conversion from Mathematica to Matlab

Hello!. I am new to the forum and I am also a newbie to programming. I want to convert a Mathematica code to Matlab, but I don't understand how to translate these lines. This code is Mathematica 5.0. defvar := Module[{a}, Clear[ cN, cNf, ginix ]; Clear[ Nh, Nhf, gini ]; cN =...
11. ### Understanding the Mass-Length Relation: Solving for V in Simple Equation

Hello, If i have this relation: ## M_p^2 = M^3_s V ## where ##M_p ## and ##M_s ## are masses in GeV and V is a length. Let ## M_p = 10^{18} ~ ## GeV and ##M_s = 10^3 ## GeV , what is V in meters ? My solution : The equation becomes ## V = 10^{30}## GeV , but ## 1 m \sim 10^{15} ~...
12. ### Turning oxygen into fluorine in our atmosphere

Summary:: Hypothetical discussion of a method to turn oxygen into fluorine through the use of another chemical and also discussing the biological effects of fluorine. Hello, I'd like to start this by saying my knowledge of chemistry is extremely basic. I barely graduated chemistry in high...
13. ### Convert cylindrical coordinate displacement to Cartesian

Summary: I can't figure out how the solver carries out the conversions from cartesian to cylindrical coordinates and vice-versa. I have a set of points of a finite element mesh which when inputted into a solver (ansys) gives the displacement of each node. I can get the displacement values of...
14. ### Moment of Inertia and units

Calculating moment of inertia and translating it between units, I've become confused. The example is a mass of 1kg at 2000mm from the pivot. The force is applied at 1000mm from the pivot. Basics as far as I'm aware: Moment of inertia = mass * Distance to center of rotation^2 Torque = Moment...
15. ### B How to find inverse steradian from arcmin^-2 for density of galaxy

Hello, I am using a code on EUCLID future mission. The original author of this code has set a value for the density of galaxy equal to : ng = 354543085.80106884 I think this is expressed in inverse steradian. I think that EUCLID mission has a 30 arcmin^-2 value for density of galaxies...
16. ### Convert solar radiation from Joule per cm square to Watt per meter^2?

I have solar radiation data in the units of Joule per cm^2 (joule per square centimeter) measured hourly. I want to use this data in evapotranspiratin calculation which requires radiation units as Watt per meter squared. How can I do this conversion?
17. ### Imperial-Metric Unit conversion for Magnetic Field Gradiometer?

Hi all, I have a question which I think should be a simple solve for most people but I cannot seem to get my head around it. It is a common case in geophysical surveying that a magnetic field vertical gradiometer might be used. This instrument uses two magnetometers separated by a known...
18. ### Information on Different Systems of Units and Measurements

Hello everyone! I would like to ask a rather comprehensive question. I would appreciate it if you could help me with this. I have started reading a chemistry textbook recently and typically in the first chapter of any basic chemistry course, you come across, measurement, unit conversion, etc...
19. ### Help converting the NIST spectrogram of Calcium

I am not a physics major and don't know even where to start trying to interpet this spectrogram from the NIST website of the element Calcium https://physics.nist.gov/PhysRefData/Handbook/Tables/calciumtable2.htm My goal is to find a way of converting this spectrogram into a tone or frequency...
20. ### How to write the complex exponential in terms of sine/cosine?

I apologize in advance if any formatting is weird; this is my first time posting. If I am breaking any rules with the formatting or if I am not providing enough detail or if I am in the wrong sub-forum, please let me know. 1. Homework Statement Using Euler's formula : ejx = cos(x) + jsin(x)...
21. ### Simple Unit Conversion Word Problem Help

Homework Statement During a heavy rain, a section of mountainside measuring 2.5 km horizontally, 0.80 km up along the slope, and 2.0 m deep slips into a valley in a mud slide. Assume that the mud ends up uniformly distributed over a surface area of the valley measuring 0.40km x 0.40km and that...
22. ### Physics Homework Help of converting to years (astronomy q)

A star is 3.7 x 104 ly (light-years) from the center of its galaxy and is moving in a circle around that center at a speed of 170 km/s. (a) How long does it take the star to make one revolution about the galactic center? (b) How many revolutions has the star completed since it was formed about...
23. ### Unit conversion meters Newtons years seconds

Hi, I need to convert a value of 12*10-16 m7 N-3 y-1 to the units of kPa-3 m2 s-1. Can anyone help me? where: m = meters, N = Newton, y = year, s = seconds. Thanks!
24. ### Unit Conversion of Flux: Jansky to Erg/s/cm²/Å - Simplified Guide

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...
25. ### Confused with the relationship between Volts, Current, and Power

Homework Statement For an engineering assessment (first year with no electrical background), we are using a solar panel to power an element for a distillation system. we have calculated our heat energy output requirement that we need from our heating element as being 800 J/s. For simplicity we...
26. ### Temperature Conversions: Understanding the Use of Conversion Factors for Rates

Why is that whenever we convert a temperature, say ##^\circ C## to ##^\circ F##, we use ##T_F = \frac{9}{5}T_C+32##, but whenever it involves a rate, say ##^\circ C/m##, we only multiply by the slope of the previously given formula? I would say it's because of the latter being a rate so...
27. ### Motion graphs and their units

Homework Statement I'm having some issues with the following exercise: The graph below represents the marking of a vehicle speedometer in funtion of time. Elaborate the corresponding graphs of acceleration and space traveled in function of time. What is the average acceleration of the vehicle...
28. ### B The fundamental units in Physics

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...
29. ### Expressing concentrations as a percent

You measure the concentration of O2 in seawater to be 5.0 mg O2/L H2O. Express this concentration as a percent. Question 2: The Earth's atmosphere contains 21% O2/L of air. How much more oxygen does the atmosphere hold than seawater from the previous question? So for question one I got 0.01%...
30. ### How do I convert cubic picometer to cubic centimeter?

Part of the question says: An unit cell has a cell edge of 288 pm. I got to the part where volume (288 pm)^3 = (288 x 10^-10 cm)^3 I have no idea how that equals 2.39 x 10^-23 cm^3 Only the Bold part ^
31. ### I Find Oven Temperature at various moderate mode?

Hello, I want to convert gas unit into oven temperature (Fahrenheit, Celsius). Which formula I can use? Also I want to know at which oven temperature we can assume it as moderately high or cool temperature??
32. ### I want to replace an AC motor with a DC motor

Ac motor is 1.12 amp 3000 rpm 60 Hz 1/30 Hp sealed ball bearing. I want to use a 12 V dc motor. Any help would be greatly appreciated. Thank you.
33. ### Fischer-Tropsch Conversion / Kinetics

Hi, We are currently working on a small-scale Fischer-Tropsch process. The modeling software we are using is HYSYS (Aspen). We want to produce X barils of oil / day using syngas (H2:CO ratio 2:1) using cobalt catalysts. The problem we are currently facing is that we do not have the kinetics...
34. ### Finding Surface Area in square feet with Volume & Thickness

Homework Statement How large a surface area in units of square feet will 1 gallon of paint cover if we apply a coat of paint that is 0.1cm thick? Homework Equations Since Volume is L * W * H and we can assume the object is square besides the height which in this case will be the thickness. So...
35. ### Piston Pressure and Unit Conversion

Problem: CO2 is contained in a vertical cylinder at a pressure of 30 atm by a piston with a mass of 57 lbm. If g is 32.4 ft/sec2 and the barometric pressure is 29.7 in. Hg what is the area of the piston? Relevant equations F = Ma/gc W = Mg/gc P= F/A gc = 32.174 lbm ft / (lbf sec2) 1 atm = 29.9...
36. ### Burnup Conversion: Convert MWd/kgU or GWd/tU to %

Is there a conversion method to convert burnup from MWd/kgU or GWd/tU into % ? Always assuming that the fuel is UO2 with ~ 200 Mev per fission.
37. ### I How to Convert Cgs to SI Units for Flux and Energy Values?

Hi I have a value that is 10.7 mJy, that I need to convert to SI units. I thought it would be 1.7*10^(-2)*10^(-26) but that might be wrong? Then I have a flux value, kappa, of 2 cm^2.g^(-1) that needs to be converted to meters and kilogram. I thought it was 2*10^(-7) m2/kg, but that might be...
38. ### How to Convert Capacitance in cm to Farads for a Transmission Line Experiment?

Homework Statement Basically I have to convert from Gaussian Units in a Transmission Line Experiment. I don't get what the point of expressing Capacitance in cm is and I find this very confusing. Homework Equations The equation I've been given is C'=Q'/V=w/4πh, (1) where the prime denotes "per...
39. ### I Explain the formula, rpm unit conversion

Revolutions(RPM) * Pi/30 = Angular velocity What is the purpose of pi/30 in the equation. Why can we not just use rpm as unit of measure of angular velocity?
40. ### Specific Gravity of a Brine

Hello all, I am currently trying to convert brine salinity values in ppm to the corresponding brine density. My understanding is that I can do that using ppm * SG = mg/L . However I do not know how to get the Specific Gravity (SG) of my brine. The data I try to convert has a minimum value of...
41. ### Potential energy to watts

Could anyone help me with this sum - To generate electricity, 180000 kg water is dropped from a height of 50 m (let g = 10 m/s^2). If half the gravitational potential energy is converted to electric energy, how many 100 W bulbs can be lit ? Formula - Ep = mgh I calculated the potential energy...
42. ### Converting kW/h to kWh for Optimizing Fuel Cell Ramp-Up

Hi everyone, I am working on a mathematical optimization model for a fuel cell. Currently I am facing a problem with the ramp-up of the cell. I have a modulation ramp of 4% of the nominal power (58.3 kW) per minute. My constraint in the model has to be in kWh (I have to precise that my...
43. ### 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...
44. ### 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...
45. ### Convert absorption coefficient units between Hitran, Lifbase

Hi, I have some modelling code that uses data from Hitran 2012 (https://www.cfa.harvard.edu/hitran/Download/HITRAN2012.pdf). I want to use some data from Lifbase but unfortunately the absorption coefficient units do not match. Lifbase units are given in m3 J-1 s-2 whereas Hitran units are...
46. ### Hexidecimal to Binary question

Homework Statement After being given a decimal base 10 #: 716, I've converted it to hexidecimal and got 2CC. However, if I want to convert 2CC to BINARY, do I find numbers of base 2s that ADD up to 716 ( 1011001110) OR do I find binary values for 2 , C , C separately? (Such as 0010 1100 1100)...
47. ### A strange inconsistency when calculating area with decimals

I have a question about a seemingly illogical and strange aspect of multiplication and unit conversion that I have never noticed until now. It concerns the issue of finding the area of a square/rectangle when the length and width are expressed as decimals/fractions. Ordinarily, when you find...
48. ### Simple conversion problem

Homework Statement The density of water is given to be 1000kg/m^3 use unit conversion to show a cube of water with a side length of 10cm has a mass of 1kg. Homework Equations mass=volume x density The Attempt at a Solution 1000kg/m^3*1000cm^3*1m/100cm*1m/100cm*1m/100cm=.01kg all meters and...
49. ### 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
50. ### How do I convert from kJ/kg to kJ/mol?

I have researched that isobutanol has a heat of combustion of 35981 kJ/kg; however I need this to be in kJ/mol. From calculations, the molar mass of isobutanol was found to be 74g/mol. How would I go about in converting this? Relevant equations (?) #mols=mass/molarmass But how can I use this?