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Lenz's law, named after the physicist Emil Lenz (pronounced ) who formulated it in 1834, states that the direction of the current induced in a conductor by a changing magnetic field is such that the magnetic field created by the induced current opposes the initial changing magnetic field.
It is a qualitative law that specifies the direction of induced current, but states nothing about its magnitude. Lenz's law explains the direction of many effects in electromagnetism, such as the direction of voltage induced in an inductor or wire loop by a changing current, or the drag force of eddy currents...
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The last weeks and days have seen some erratic behaviour by Stack Exchange Inc., such as likely illegal changes to the content license and the firing of an upstanding community moderator with no explanation except copy-pasted responses (leaving many to believe it was for no good reason). It wou...
The Carnot cycle is a theoretical ideal thermodynamic cycle proposed by French physicist Sadi Carnot in 1824 and expanded upon by others in the 1830s and 1840s. It provides an upper limit on the efficiency that any classical thermodynamic engine can achieve during the conversion of heat into work, or conversely, the efficiency of a refrigeration system in creating a temperature difference by the application of work to the system. It is not an actual thermodynamic cycle but is a theoretical construct.
Every single thermodynamic system exists in a particular state. When a system is taken through...
A rack and pinion is a type of linear actuator that comprises a circular gear (the pinion) engaging a linear gear (the rack), which operate to translate rotational motion into linear motion. Driving the pinion into rotation causes the rack to be driven linearly. Driving the rack linearly will cause the pinion to be driven into a rotation.
For example, in a rack railway, the rotation of a pinion mounted on a locomotive or a railcar engages a rack between the rails and forces a train up a steep slope.
For every pair of conjugate involute profile, there is a basic rack. This basic rack is the profile...
A turbine (from the Latin turbo, a vortex, related to the Greek τύρβη, tyrbē, meaning "turbulence") is a rotary mechanical device that extracts energy from a fluid flow and converts it into useful work. The work produced by a turbine can be used for generating electrical power when combined with a generator. A turbine is a turbomachine with at least one moving part called a rotor assembly, which is a shaft or drum with blades attached. Moving fluid acts on the blades so that they move and impart rotational energy to the rotor. Early turbine examples are windmills and waterwheels.
Gas, steam, and...
Fuel saving devices are sold on the aftermarket with claims to improve the fuel economy and/or the exhaust emissions of any purport to optimize ignition, air flow, or fuel flow in some way. An early example of such a device sold with difficult-to-justify claims is the 200 mpg carburetor designed by Canadian inventor Charles Nelson Pogue.
The US EPA is required by Section 511 of the Motor Vehicle Information and Cost Savings Act to test many of these devices and to provide public reports on their efficacy; the agency finds most devices do not improve fuel economy to any measurable degree, unlike...
I want to find the natural frequency of a two coupled oscillator system like this-
My book does it this way but I don't really get it.
The equations of motion for the pendula are-
$I\frac{d^2\theta_1}{dt^2}=−M_{eff}gL\sin \theta_1− κl^2(\sin \theta_1−\sin \theta_2)$
$I\frac{d^2\th...
I am studying thermodynamics and in the first chapter the concept of exact and inexact differentials were used to talk about the differences between internal energy, work and heat.
From Blundell and Blundell: $\Delta f=\int_{x_i}^{x_f}\mathrm df=f(x_f)-f(x_i)$.
My issue is I can not imagine a f...
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Q: Updating the Hot Network Questions List - now with a bit more network and a little less "hotness"!
Some of you may have noticed that we've been making some changes to the Hot Network Questions on the back end over the last week or so. I'm here announcing our first round of changes to how the HNQ works and give you some ideas of why we're starting here and where we're planning to go in the futu...
The Spivak pronouns are a set of gender-neutral pronouns in English promulgated on LambdaMOO based on pronouns used by Michael Spivak. Though not in widespread use, they have been employed in writing for gender-neutral language by those who dislike the standard terms "he/she" or singular they.
Three variants of the Spivak pronouns are in use, highlighted in the declension table below.
The original ey has been argued to be preferable to e, because the latter would be pronounced the same as he in those contexts where he, him, his loses its h sound.
== History ==
The precise history of the Spivak...
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