jbriggs444's latest activity
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jbriggs444 reacted to Herman Trivilino's post in the thread Graduate How valid is the Block Universe theory? with
Like.
Oops. I had to go back and edit that post about 3 times because I kept making mistakes. Too early in the morning maybe? Oh well, what's... -
jbriggs444 replied to the thread Undergrad First law of this universe.Global conservation of mass is a feature of classical mechanics. Local conservation of stress energy is a feature of general relativity...
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jbriggs444 replied to the thread Undergrad First law of this universe.Height is not conserved. Nor is it usually additive. That makes it less meaningful and less useful to speak about height "moving". We...
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jbriggs444 replied to the thread Undergrad First law of this universe.Nor do I. To the extent that energy is localized and conserved, it may be sensible to speak about energy moving. We could, for...
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jbriggs444 reacted to haruspex's post in the thread If Heat Is Motion, Why Isn’t All Motion Heat? with Like.
Is it that clear cut? For a pair of contra-rotating discs there is a frame which minimises the KE but it is still substantial, and most...
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jbriggs444 replied to the thread Why Are You Still Here? A Curious Question.When someone speaks of freedom from censorship as a virtue, I like to think back to Usenet. The lesson learned there was that...
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jbriggs444 replied to the thread Finding proper value for centripetal acceleration in a plane rising up.Right. You are asked for velocity. You have determined the [coordinate] acceleration. That is all you need. The various forces required...
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jbriggs444 reacted to Lnewqban's post in the thread Finding proper value for centripetal acceleration in a plane rising up with Like.
The value of the increased lift force at the bottom of the loop is the only net force that induces the airplane to deviate from a level...
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jbriggs444 reacted to haruspex's post in the thread Finding proper value for centripetal acceleration in a plane rising up with Like.
Centripetal acceleration is the component of acceleration that is normal to the velocity. If the plane is flying level, its lift is g...
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jbriggs444 replied to the thread Finding proper value for centripetal acceleration in a plane rising up.The professor is still wrong. Let us grant that the intended threshold for pilot unconsciousness is 6g of coordinate acceleration. This...
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jbriggs444 replied to the thread Finding proper value for centripetal acceleration in a plane rising up.Loss of consciousness results from proper acceleration, not coordinate acceleration. Proper acceleration is how much the plane's...
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jbriggs444 replied to the thread Voltage that gives acceleration to relativistic particles.Yes.
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jbriggs444 reacted to Antoha1's post in the thread Voltage that gives acceleration to relativistic particles with Like.
do I understand correctly: Relativistic mass is just total energy so the energy ratio is 3Ep=Ea and I can manage everything with 2 first...
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jbriggs444 reacted to Baluncore's post in the thread High School Is it safe to fly in a spinning hollow asteroid? with Like.
If you threw a ball to a person ahead of you, would the ball plunge towards their feet. If you threw the ball to someone behind you...
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jbriggs444 replied to the thread Voltage that gives acceleration to relativistic particles.When the question asks for mass, do you understand it to mean relativistic mass or invariant mass? Obviously one can discard the idea...