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Acceleration of a rocket
Hey guys, I want to know if I have an equation on thrust correct. I figured whats the acceleration as a function of time. You have the upward thrust = dm/dt v, assuming the mass flow rate and the gas...
View ArticleRotating disk/ sphere and moving mass along it
Coriolis effect - In a non-friction system, f I roll something along the surface of the planet from on of the poles to the equator, it will appear to move to the west, it will essentially stay behind...
View ArticlePoles of a broken magnet
Hi, Recently I came across an annular permanent magnet (round magnet with a hole in it) which had fallen and broken in half, effectively forming two horse-shoe magnets. I noticed that the two halves...
View ArticleDefinition of a force
0k i know net force on a body is defined as mass times acceleration of the body w.r.t inertial frame, but how do we define individual forces acting on the body? Eg. Forces acting on a 1kg block are...
View ArticleDistance from earth an object would have to fall from to reach speed x
big G = G = 6.674E-11 N(m/Kg)^2 Mass of earth = Me = 5.972E24 Kg Radius of earth = Rsurface = Rs = 6.371E6 metres THIS IS NOT HOMEWORK Okay so I was interested to know how you would work out the...
View ArticleElectric polarization
Does the electric polarization density of a dielectric inside a capacitor have the same direction as the electrical field? Considering the electric dipole moment vector goes from the - charge to +...
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Direction of Axle Force on Pivoted Disk
Hello everyone, I came across this problem from my Physics textbook. I do not understand why the direction of the axle force is pointing downward. I think the upper part of the disk is exerting a...
View ArticleA Problem with Two Current-Carrying Wires
We all know that there is a force between them. But I wonder... if electrons in both wires are moving with the same speed the relative velocity between the electrons in wire A and B equals zero - but...
View ArticlePermanent magnet questions
Im looking to do some projects with permanent magnets. I dont have access to a gaussmeter and i'm wondering if there are any sites that have representations, descriptions or formulas for the field...
View ArticleHelp Calculating RPM of a rotatory atomizer thats powered by pneumatic
Hello everyone, I am a recent horticulture graduate and as such, I take a long time figuring out physics problems.:confused: I hope I could trouble you guys for a possible solution to my problem. I am...
View ArticleFundamental Thermodynamic Relation and Helmholtz Energy
I'm confused about the condition for spontaneity for the Helmholtz energy. My textbook (McQuarrie, "Physical Chemistry") derives the conditions as follows. We start with the combined law of...
View Articlethe way the potentiometer measures
I may have a misconception about the way the potentiometer measures thermal emf... (Seebeck effect... Fe,Cu...the two points where these two wire are connected are at different Temperature... So there...
View ArticleDifference between enthalpy, Helmholtz free energy,& Gibbs free energy
I am study chapter 5 of An Introduction to Thermal Physics by Schroeder and I am having trouble understanding his explanation of the differences between enthaply, Helmholtz free energy, and Gibbs free...
View ArticleWhy is kinetic energy 1/2 mv^2?
This is probably a stupid question because the answer is likely "it just is". I am reading Calculus: The elements by Michael Comenetz, and when talking about mQ, he goes on to say "there happens to be...
View ArticleSolving problems in Kinematics with simple calculus
Hi, I have a generic question about solving kinematic problems using simple calculus. For eg. A variable force F = bv (v is instantaneous speed at some time t) acts on a vehicle moving with speed v....
View ArticleS2 - S1 > Integral 1-2 dQ/T Irreversible Process. What T ?
For an irreversible process: S2 - S1 > ∫12 dQ/T In the case of heat transfer dQ between object with T1 to object with T2, T1 > T2 ΔS in Joules/K is known But for evaluating ∫12 dQ/T = ln dQ/T -...
View ArticleFinding strength, pull, telsa (anything) of an electromagnet
I have built a new electromagnet, my second one so far, in an attempt to make it better. I am trying to find its strength, whether that be in tesla, holding force (kg) or whatever other units there...
View ArticleTransfer of heat by radiation and Second Law of Thermodynamics
Second law of thermodynamics states that heat does not flow spontaneously from cold to hot bodies. But a cool fluorescent bulb is perfectly capable of heating something that had already started out...
View ArticleS≥k equivalent to thermodynamics and thermostatics??
Is it true that all thermostatics and thermodynamics can be deduced from the supossition that entropy S for all observers is S≥k, where k is Boltzmann constant. A book when does it come explained??
View Articletheory of Structured illumination microscopy
Hi all, My question concerns the theory of how super resolution microscopy causes a frequency shift to allow information normally outside of the observable region of frequency space to be captured by...
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