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5

Photons mediate the electromagnetic force. Atoms are not necessary for photons to exist. You just need charged particles (electrons, protons, etc) to interact with each other from a distance. There are many ways for a photon to be created and destroyed. Depending upon its wavelength, as it propagates in free space , it could "disappear" and a pair ...


5

Here is a flow chart of the forms of energy, with links . Conservation of energy is one of the fundamental laws governing physical systems and is the only reason why one can talk of "negative energy" here is a breakdown of the forms that **Conservation of energy ** takes In almost all frames negative energy exists, in the sense of conservation of ...


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As a general rule adding thermal energy doesn't cause electronic transitions. That's because typical electronic transition energies are a few electron volts or around 100kT at room temperature. In a metal the electrons aren't in discrete energy levels but instead reside in a continuous band of energy levels called the conduction band. While thermal energy ...


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Wood is a poor conductor Oven-Dry Wood has a resistivity of $1.00 \times 10^{14}$ to $1.00 \times 10^{16} \Omega m$ Damp Wood has a resistivity of $1.00 \times 10^3$ to $1.00 \times 10^4 \Omega m$ Copper has a resistivity of $1.68 \times 10^{−8} \Omega m$


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The obvious method is to burn a barrel of crude oil and measure how much energy is released. The only slightly less obvious method is to burn a small amount of oil and measure how much energy is released, and then mathematically figure how much energy a whole barrel would release, as @CuriousOne points out. The latter method is superior in both the ...


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The easiest way I can think of to get some idea of this is to sit by your water heater and listen to it. Assuming you (and no one else) has used any hot water recently (like, within the last hour or so), and that no one uses any more hot water for the duration of this experiment, then the water heater will turn on only to maintain a relatively constant ...


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Your question What is the potential energy of a black hole? doesn't make sense because energy is a somewhat tricky concept to deal with in GR. If we treat the black hole as fixed we can study the motion of a test particle falling into it, and we find that there is a quantity analogous to total energy that is constant as the particle falls in. So in ...


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Black holes are in the realm of General Relativity. In GR even the law of conservation of energy is under question when approaching singularities of the GR solution. Potential energy is a concept that comes with conservation of energy. Where the singularity in the black hole solutions is dominating, one cannot talk in terms of energy conservation and ...


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The helicopter and the power lines are at different potentials, the difference being so great as to cause the air in between to become a conductor. If you applied such a potential difference across a line worker it would probably result in death. You will note that the line worker is holding a metal stake which has a "pointed" end. This increases the ...


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Assume the power of the microwave oven to be $P$ and that the instructions for cake and custard lead to the same temperature ($T$) of both when they are heated separately, then: $t_1=\frac{m_1c_1(T-T_0)}{\epsilon P}$ and : $t_2=\frac{m_2c_2(T-T_0)}{\epsilon P}$ where in the indices $1$ and $2$ refer to cake and custard, $m$ the mass, $c$ the specific ...


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The small object exerts a force in the opposite direction to the normal force on the cart


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Heat transfer can occur by conduction, by convection, and by radiation. If you consider conduction through the bulk of the cup, the rate of heat transfer is directly proportional to the temperature difference across the material of the cup. As your experiment holds all variables equal except the temperature difference, cup A will lose heat at a faster rate ...


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What would happen if you were to release the energies of the big bang in our universe a second time? Have a look at this standard history of the universe, History of the Universe - gravitational waves are hypothesized to arise from cosmic inflation, an expansion just after the Big Bang Our universe is now at the far right. Note the beginning ...



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