# Tagged Questions

Energy is the conserved quantity associated to time-translation invariance and represents the work a system is capable of doing. Use this tag for questions about energy, and consider adding [tag:energy-conservation] if it is specifically about its conservation.

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### How to heat water to 80°C? [closed]

I'm trying to figure out an easy water to get 80°c to consistently make the perfect cup of coffee. Let's assume room temperature water is 22°c. What is the ratio of boiling water to room temp water ...
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### Energy of a standing wave

I've been taught that energy of a standing waves remains between the nodes of the wave or in other words energy remains within the wave. I wanted to know how that's possible. Also if energy of a ...
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### why doesn't liquid metal vaporize in a vacuum?

I am wondering why molten metal in a vacuum of electron beam and machines never turns to gas like liquid water does when exposed to a vacuum.
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### Particle with 1 GeV mass?

I know a proton as a mass of 0.938 GeV also neutron at 0.939. But I was wondering if there is anything with a measured mass of 1 GeV? Or, whether a proton can have a mass of 1 GeV within a system (as ...
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### Work functions of ceramics/insulators

Is anyone aware of or know of a good source or means of estimating the work function of a ceramic material? Typically, work functions are given for pure elemental metals, rather than for compounds, ...
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### Is there a generalized notion of intrinsic charges which describes a general interaction?

Consider classical fields. Lots of parallels can be drawn between different kinds of fields because they are fundamentally similar. Mass can be viewed as a mass charge, [charge] can be viewed as an ...
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### Where does the energy within atoms come from?

Most kinds of energy I know about involve a finite measurement and are transferred. In other words, energy in the universe is finite and is not lost or gained but only transferred through space one ...
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### Energy stored in a coaxial cable before reaching breakout field

Yesterday I had a (multiple choice) exam and the following was one of the questions. We have a coaxial cable (basically two coaxial conducting cylinders) with the inner radius of $a$ (variable) and ...
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### Where does the energy of the electric cable come from?

I'm stuck on one really simple example, I can't figure out what's happening to energy here... (This is not homework) Let's consider an uncharged electric cable, we'll model it by an infinite ...
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### Conservation of energy during rolling without slipping?

Say there's a cylinder laying on a flat surface, and the surface is rested on frictionless ice. Attached to the surface is an engine that is attached via a string to the center of the cylinder, and (...
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### Necessity of the Notion of Work and Kinetic Energy

I've worked through many example problems in my college physics text in the section on kinetic energy and work. I noticed that if the desired quantity is velocity or force, they can be solved entirely ...
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### Are sound waves adiabatic or isothermal?

I am doing a presentation on sound waves and I need to know if they are adiabatic or isothermal. I know that they can generate heat, but is the amount of heat created so small that it can still be ...
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### Is the work-energy theorem valid for only particles or rigid bodies as well?

Is the work-energy theorem valid for only particles or rigid bodies as well? Most places where I have read this seem to claim the latter. But an example I thought up has been troubling me. Consider ...
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