2013年4月3日 · I understand that Emf and Voltage both have the unit Volts, and Work Done and Energy both have the unit Joules, so V=W/Q and Emf = E/Q are basically the same equation. And I also understand that it is convention to call the voltage across a battery V, and the voltage it would theoretically have across it if it had no internal resistance emf.

2014年8月24日 · Stack Exchange Network. Stack Exchange network consists of 183 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

2013年3月9日 · 2. The sign of W depends on the convention chosen (whether work done on the system is positive or work done by the system), physicists and engineers often use different conventions (I count both work and heat done on the system as positive). 3. ##Q=\Delta U-W##. In reversible processes ##\Delta H=Q## at constant p and ##\Delta U=Q## at constant V.

2014年8月9日 · Due to heat transfer, the gas expands and pushes the piston that is doing the work.If the amount of heat transferred from the surrounding to the system $\pu{400\text{Joule}}$, and the amount of work done by the system was $\pu{300\text{Joule}}$, the change in the internal energy of the system $\Delta{E}$, is: $$\begin{array}{ } \Delta{E}~~~=~~q ...

2020年11月6日 · $\Delta U = \Delta Q + \Delta w = \Delta Q -p\Delta V$ For the engineers, the internal energy is the fraction of the energy (heat) that is "lost" in the system, and that has not been used for producing work.

2013年1月8日 · [as 'J' relates W & Q with a multiplication and not addition or substaction] the equation was not given while solving a problem , but was stated like it is a basic formula. By looking through other worked problems in that textbook you should be able to deduce the system of units that book uses.

2019年5月22日 · Vacuum: This follows $ΔU = Q$. There is no surroundings to do work on, so all of the expansion energy goes into slamming the piston against its backstop, and after everything settles this ultimately results in the full $\pu{1 J}$ of heat …

2009年6月16日 · The formula [itex]V=k\frac{q}{d}[/itex] gives the potential at a distance d. This formula is only valid for point charges. The formula [itex]W=qEd[/itex] is the work needed to move a charge q in an electrical field E a distance d. The general formula is W=qV, for a uniform electrical field V=Ed.

2008年2月26日 · For point charges within an electric field, the natural direction a point charge takes in respect to a field would be towards lower potential energy, whereas the work done by the conservative force should be positive. So then, by W = -q*deltaV, do they refer to the magnitude of the test charge...

2022年1月5日 · It’s worth noting that in the context of circuits, the symbol ‘w’ (or 'W') is often loosely used for any type of energy transfer, e.g. heat dissipated in a resistor. Here’s a trivial circuit example: when 3C of charge pass (at a constant rate) through a bulb 6J of energy are dissipated as heat and light.