Substance evaporation temperature
Can a substance only evaporate at the T(sat) at that particular pressure and why not even at a higher temperature? Example of a refrigerant at room temperature, pressurized container. But when it's...
View ArticleElectric field at a distance from a charged disk
A disk of radius 2.4 cm carries a uniform surface charge density of 3.1 μ C/m2. Using reasonable approximations, find the electric field on the axis at the following distances. I have used the equation...
View ArticleWhat exactly is an inertial reference frame?
Due to my job and other classes, I've been studying ahead of my class by myself to not fall behind and I'm not sure if I'm oversimplifying this in my head and not really grasping the idea. Newton's...
View Articleseeking derivation of real scalar field Lagrangian
Here and there I come across the following formula for the Lagrangian density of a real scalar field, but not a deriviation. [tex] \mathcal{L} = \frac {1}{2} [ \dot \phi ^2 - ( \nabla \phi ) ^2 - (m...
View ArticleMost Probable Speed - Atoms From An Oven
Hi there, I'm looking to find the most probable speed of atoms ejected from an oven. Temp (T) is 900°C (so 1173.15K). The material is aluminium with molar mass 0.027kg mol-1 I've got the formula...
View ArticleCalculate Rate of Disintegration of Projectile
I was thinking about meteorioids and how upon their entry into the atmosphere the large amount of disintegration they experience so i wanted to try running through a calculation of something similar to...
View ArticleClik here to view.
Torque on a hub as a result from a flexible arm
I'm working on a research project as a graduate student in engineering. I'm modeling a set of equations in Simulink and MATLAB derived from a journal entry. I'm a little rusty on classical mechanics as...
View ArticleWhy the thermoelectric emf doesn't depend on the lower temperature of the...
Why the thermoelectric emf doesn't depend on the lower temperature of the thermocouples... And why does the emf start to decrease after a certain increase of temperature?
View ArticleWhat electromagnetic range would disrupt a neodymium magnet?
Hello all, This is just a question i have... I need to know the frequency (in order to meter it) from an electromagnetic source, and i know that a neodymium magnet will disrupts it. so, i want to know...
View Articledrift velocity in a conductor
Dear all, I have a question on the derivation of the drift velocity in a conductor, and was wondering if somebody could help me with it: drift velocity is the average velocity which a free charge...
View ArticleWeight of a fluid when I put my finger in it
Hi. I was asking myself the following question. What happens if I have a fluid at rest inside a container, and I introduce my finger in it without applying any force to the walls? Will the weight of...
View ArticleFluid mechanics: Flow and velocity of a fluid
I've rencently been thinking about several systems related to fluid mechanics, and I've asked myself the following question: If I have a cylidrical tank with a small hole in the bottom (the surface...
View ArticleClik here to view.
Predicting Lorentz force fluid particle trajectories
I am trying to understand how the Lorentz force affects bulk fluid motion when I have an applied electric field (y-axis), applied magnetic field (x-axis) and bulk fluid velocity (z-axis), all...
View ArticleClik here to view.
Gyro vs. Flywheel problem
I have a problem which got me thinking, but I'm unable to solve to my satisfaction. The problem involves a gyro attached to a platform which in turn is attached to a flywheel. (See image below) The...
View ArticleProbability Density Functions in Fluid Mechanics
Hi all, For an exam I'm required to be able to plot the PDF of a fluctuating velocity function, say u(t)=sint(wt), using what they call the "graphical technique", but handily I can't find it anywhere...
View ArticleMy Attempt At Re-entry Temp. Calculation
I wanted to figure out the temperature(t2) of any object based on things such as its specific heat capacity, re-entry speed, etc. Work: W = Fy Force by Air: FD = 1/2pv2CDA Energy-temperature...
View ArticleClik here to view.
Pressure Transmitter Installation at 410 deg C
Hi, I have an application of pressure transmitter at 410 deg C max. process temperature. Transmitter can withstand only up to 350 C at Atm pressure. The original length of tubing for maximum working...
View ArticleFresnel amplitude coefficients for unpolarized light
Hi, I have an issue with the Fresnel amplitude coefficients. I know they are given in two versions, for s-polarization and p-polarization. A version for unpolarized (randomly polarized) light is...
View ArticleThermodynamics: DT/DV at constant entropy? (last maxwell relation I haven't...
So, until now I know: (DV/DS)p=(DT/Dp)s=a*T/cp*(rho) (enthalpy) (Dp/DT)v=(DS/DV)t=-a/k (helmoltz) (DS/Dp)t=-(DV/DT)p=-Va (gibbs) a=expansion coefficient k=isothermal compression coefficent cp=heat...
View ArticleCharacterize EM wave propagate in +z and -z
For RHC EM wave travel in +z direction, the unit vector is [itex]\hat {E}=\frac{\hat {x}+\hat{y}j}{\sqrt{2}}[/itex] ignoring the ωt-kz. What if the RHC EM wave travels in -z direction? The unit vector...
View Article