# Search results

1. ### Heat exchanger for a layman

OK, I'm familiar with that pressure problem. A very simple solution (use to have that in my military base) is when you have two different pressures in the hot and cold taps (but above atmosphere): you get two pipes (hot and cold) with each having it's own separate controllable valve and connect...
2. ### Heat and Thermal Energy

In classical thermodynamics the state function is the Internal Energy which is modulated by Work done "to" and "by" as well as Heat, transferred "to" and "from". Not all Internal Energy is Thermal Energy (i.e. is not proportional to temperature) e.g. the Energy that is stored in chemical bonds...
3. ### Heat exchanger for a layman

What do you think about installing a water tap with two lines (two in - one out): hot and cold? It would dilute the hot water with cold water to a comfortable temp. Cheers. Roman.
4. ### Heat and Thermal Energy

You should understand that any net (macroscopic) Heat or Thermal Energy transfer is from "Hot" to "Cold" (the so called parcel receives radiation energy but it also radiates it away as a function on its temperature). So I claim there is no difference in your definition of Heat and Thermal...

In the annihilation of particles charge is conserved and as far as I know Electromagnetic radiation is still created by Charge (electrons and/or quarks). In a black EM radiation is, as far as I know, created by Charges and escapes the event horizon due to virtual charged particle annihilation...
6. ### Two scenarios different energy requirement?

Change in Work = Change in Potential Energy + Change in Kinetic Energy *Total distance traveled is not important as there are no fricative (tangential) forces. Cheers. Roman.
7. ### Rainfall drop velocity from a given height (not terminal!)

As I see it you need to write it in the from of a differential equation and Matlab will solve it (numericaly or otherwise): Sum( Force( V(t) ) ) = mV'(t) i.e. the sum of all the forces acting on the drop (drag ect.) - you need to write the those forces as a function of the drops velocity...
8. ### Escape probability of a particle in a sphere

Look up Brownian Motion. Cheers. Roman.
9. ### Microcantilever, different resonance modes

Do you have theoretical knowledge in how to describe any of those motions that create the resonances? Write the equations and look what is dependent of what. Cheers. Roman.
10. ### Amplitude and energy relation in optics

From what I remember the transmition coefficient is defined as the ration of the intensity that is being transmitted to the total intensity and intensity is proportional to the electric field squared. Intensity is proportional to em energy. Does it make sense? Cheers. Roman.

Basically charges affects other charge solely via EMF (photons). Roman.
12. ### Wave speed as a function of compression?

Is the beam made out off two parts of which one is under tension and the other under compression? Or what is being compressed by what? Roman.
13. ### Heat exchanger for a layman

Welcome to the forum! This is more of a educational forum you might have better luck on an Engineering forum. If the heat exchange is home made it's very hard to predict the outcome, the bottom line is that you will have to test your setup. Good luck ! Roman.
14. ### Two scenarios different energy requirement?

All the energy you put in pushing the car up the hill will not be lost. At the end destination the car rolling of the hills will move at a greater velocity thus will have greater kinetic energy than the car you didn't had to push so hard. It all could be written in vie the Work-Energy theorem...
15. ### Heat and Thermal Energy

In both cases it could be called Heat/Thermal energy transfer. In classical thermodynamics Energy can be transferred by two mechanisms: doing work and transferring heat (which is the transfer of Thermal energy). As far as I know Heat and Thermal energy are synonyms. *of course there might exist...
16. ### What happens to the heat?

Excellent question! The fact of the matter is that anything with temperature higher than absolute zero (0 kelvin) will loose heat to the surroundings via thermal radiation (electromagnetic radiation due to non-zero temperature). http://en.wikipedia.org/wiki/Thermal_radiation Roman.
17. ### This question may not come in the bracket of quantum mechanics but

Cool video! Brian tries to explain elementarily, that the illusion of solidity is caused by electron degeneracy pressure. Option No. 2.
18. ### This question may not come in the bracket of quantum mechanics but

You are correct, those are distinct. The first one, as I said, was a common answer given by physicists. The second answer is different but more interesting as it may in fact be what stops materials going through each other. I was mealy pointing the OP to the right direction, where he may find a...
19. ### This question may not come in the bracket of quantum mechanics but

A common answer: electrons repel electrons (EM force)... A more interesting answer: the electron Degeneracy Pressure.
20. ### What technologies based on quantum mechanics affect our daily lives?

As all of us know, computers affect our lives greatly. All modern microprocessors are very much affected by quantum mechanics (quantum tunneling) and we are near the limit of current silicon based transistor functionality.
21. ### What technologies based on quantum mechanics affect our daily lives?

Spintronics? The question was: "What technologies based on quantum mechanics affect our daily lives?" Personally the only person I know who's life is being affected by Spintronics is my buddy who does research in the field at the university ;)
22. ### What were the first applications of quantum mechanics to technology?

I would say atomic fission was harnessed solely by the use of the quantum theory of physics (Nuclear weapons, thermonuclear power).
23. ### Dose E=hn means quantization of energy?

One answer might be: The unit of E (energy) is a Joule, the unit of h (Plank's constant) is Joule time a second. If you want the equation to be correct you need to multiply h with something that has units of 1 over a second. Roman.
24. ### Laplace Transform Derivation?

...Remembered this post when I was using Z-Transforms and was told that they are just discrete Laplace Transforms :)
25. ### Need help in deriving this reduction formula

I tried to understand but it was too late, so please: http://www.codecogs.com/latex/eqneditor.php
26. ### What's the inverse Laplace transform of this?

One way so solve it (propably not the simplest but an interesting one) would be to use the fact that F(s)G(s) (multiplication of the functions) in Laplace plane is f(t)*g(t) (convolution of the functions) in "time" plane. L^{-1}\left \{ \frac{1}{(s^2+4)^{2}} \right \} = L^{-1}\left \{...
27. ### Engineering Mathematics

@diegojolin: find a closed expression for the sum(e^k), from 0 (or 1) to n. then equate it to the known sum then solve for n.
28. ### What are the latest therories in physics?

1. I assure you this is not homework. You are welcome to invent any test for me (I'm a B.Sc in ME). 2. I will elaborate: Ideas form the last 20 years that are not basic general relativity, nor any old ideas in classical physics and not basic quantum mechanics. By 20 years I mean ideas that are...
29. ### Jacobians, changing variables in multiple integration

Read and learn: http://tutorial.math.lamar.edu/Classes/CalcIII/ChangeOfVariables.aspx and check out: http://en.wikipedia.org/wiki/Jacobian_matrix_and_determinant
30. ### Laurent series expansion

Hi! I will help you with a full list of steps for one of the parts: \frac{4}{3(z + 4)} = \frac{4}{3(4(\frac{z}{4} + 1))} = \frac{1}{3(\frac{z}{4} + 1)} = \frac{1}{3(1 + \frac{z}{4})} = \frac{1}{3}\cdot \frac{1}{(1 + \frac{z}{4})} = \frac{1}{3}\cdot\frac{1}{(1-(-\frac{z}{4}))} =...