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 Feb 24 comment When the electric field in an electrostatic charged conductor is zero, is the potential within also zero? Sweet. Thanks for explaining! Feb 21 comment When the electric field in an electrostatic charged conductor is zero, is the potential within also zero? I know that a conducting body can have potential. I'm not sure if the one in my example does though. I understand your last paragraph, but if you can jiggle the particle at that point without doing electrical work, is the potential in that neighborhood zero? Dec 11 comment Knowing the mass and force acting on a particle, how do we derive the relativistic function for velocity with respect to time? I figured it out. I'll come back and post the answer ASAP. Dec 10 comment Knowing the mass and force acting on a particle, how do we derive the relativistic function for velocity with respect to time? I'm so stuck on this. I realize what you're saying, but lets just assume the numbers I mentioned. There must be some constant force pushing the electron, which we can find based on knowing the final speed of the electron and the distance it travels. If we know this force, we can find the speed of the electron at any given moment and thus the length contraction that the electron observes at any given moment and then calculate the rate of change of the contraction which is proportional to the rate of change of the velocity of the electron. Dec 7 comment Why does a gas get hot when suddenly compressed? What is happening at the molecular level? Its so hard to visualize. To me it seems that in order for the particles of the thermometer to move at the same average speed, the gas particles would have to be slower if they are more concentrated, although I know you are saying this doesn't happen. SO what happens if you put a mercury thermometer inside a vacuum (the vacuum is in a room at room temperature, but the thermometer floats magically inside the vacuum without contacting to the outter surroundings of the vacuum)? What will its temperature read after equlibrium (assuming no radiation hits it)? Dec 7 comment Why does a gas get hot when suddenly compressed? What is happening at the molecular level? @RonMaimon Wow, very interesting! I'm still confused though. I keep imagining that since there are more molecules per unit volume after compression (higher density of molecules) that there will be more molecules hitting the thermometer and that even though they have the same speed after reaching equilibrium, they will transfer more energy to the thermometer because there is a higher number collisions to the thermometer. Why is my thinking in that case wrong? Is there something I'm overlooking? Dec 7 comment Why does a gas get hot when suddenly compressed? What is happening at the molecular level? @AdirPeretz I say the temperatures are the same, but I also said we have allowed the new volume to reach thermal equilibrium. The higher temperature is experienced before thermal equlibrium is reached. Dec 7 comment Why does a gas get hot when suddenly compressed? What is happening at the molecular level? I think this merits an entirely different question: Do gas molecules in a bigger volume with move at the same speed as gas molecules of the same type in a smaller volume when both volumes have the same temperature? Dec 7 comment Why does a gas get hot when suddenly compressed? What is happening at the molecular level? Also, lets imagine that the wall only moves when there are no collisions happening, and that the wall stops for an instant when a ball needs to bounce off it, thus not changing the speed of the ball which loses no energy to the collision. So, now, the volume is small and all the balls have the same speed as before. Now, lets imagine we allow for energy to be lost to collisions. This is where I imagine that the increased temperature comes from because now more balls hit the wall, releasing energy at a higher rate due to more collisions than before. Is this the case? Dec 7 comment Why does a gas get hot when suddenly compressed? What is happening at the molecular level? Ok, so question: once the system has cooled off in temperature and reached equilibrium with the surroundings, is the average speed of each molecule the same as it was before being compressed? Nov 29 comment What does the differential of $d_s\sin(\theta) = m\lambda$ help us see, with respect to waves through diffraction gratings? In this new light (better verbage), I'd rather just use the original equation (not its derivative) since I already know what the equation is and don't have to worry about finding any sort of anti-derivative. Nov 29 comment What does the differential of $d_s\sin(\theta) = m\lambda$ help us see, with respect to waves through diffraction gratings? Thanks. Nice info. This is what I realized when I replaced the word "differential" with "derivative" which makes SO much more sense! I couldn't understand what they meant by the second equation being the differential of the first. It makes more sense to say that the second equation is the derivative of the first and can be used to find small differentials of the values in the first equation. Nov 29 comment What does the differential of $d_s\sin(\theta) = m\lambda$ help us see, with respect to waves through diffraction gratings? Aaah true, so "diffraction of waves through small slits." Feb 27 comment What is the name and value of the constant that relates to electrons and that coincidentally has the same exact value as the speed of light? hahaha.. well too bad my reputation can't go below 1. ;) Feb 27 comment What is the name and value of the constant that relates to electrons and that coincidentally has the same exact value as the speed of light? lol.. but isn't there ONLY one such constant? I just can't recal what it's called... but it's very interesting!