jbriggs444's latest activity
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jbriggs444 replied to the thread A A single molecule diffusion in ideal gas.In a head on impact, yes. But not all impacts are head on. -
jbriggs444 reacted to haruspex's post in the thread Chain falling out of a horizontal tube onto a table with
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It might help to treat the mouth in more detail. Say it is a smooth quadrant of radius ##r##. We are interested in the limit as... -
jbriggs444 replied to the thread Chain falling out of a horizontal tube onto a table.Let us reverse engineer that equation. It would have been nice to have you provide the justification for your own equations. You are...
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jbriggs444 replied to the thread Can you get pulled under a train?."Wrong Way Peach Fuzz" at your service.
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jbriggs444 replied to the thread Can you get pulled under a train?.But what if one of the carriers is running in reverse? Then two right sides are available.
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jbriggs444 replied to the thread A A single molecule diffusion in ideal gas.Surely the new random velocity is not obtained directly from the Maxwell distribution. The distribution of resulting velocities should...
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jbriggs444 replied to the thread Is it possible for a vertical rod balancing on a table to lose contact by striking the top of the rod?.I just tossed a pen in the air, giving it an end over end spin. The laws of physics did not prevent it.
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jbriggs444 replied to the thread I The rocket equation, one more time.dx/dt is not positive by definition. It can be either positive or negative. If ##x## is a differentiable and strictly monotone...
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jbriggs444 replied to the thread I Acceleration on an electric unicycle, how much does the rider have to lean?.I can ride a real unicycle. One cannot spontaneously lean forward. Instead, one pedals slightly back. This moves the contact point...
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jbriggs444 replied to the thread Chain falling out of a horizontal tube onto a table.The "it" in that passage is the tube. The top of the tube exerts a downward force to impart downward momentum to the chain. The right...
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jbriggs444 replied to the thread Chain falling out of a horizontal tube onto a table.A leftward force to bring the chain to a stop horizontally. And a downward force to bring the chain to a matching rate of motion vertically.
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jbriggs444 replied to the thread Chain falling out of a horizontal tube onto a table.The drawing shows the chain descending vertically. Not in some sort of [evolving!] parabola. This implies that the chain is constrained...
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jbriggs444 replied to the thread Collection of Lame Jokes.They just haven't been exposed to an orthogonal instruction set...
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jbriggs444 replied to the thread I Conservation of angular momentum in the iceskater example.As the skater's hands are pulled in, they trace out a spiral trajectory. A purely radial force has a non-zero component along the...
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jbriggs444 replied to the thread I Is calling fictitious forces "not real" just about terminology?.I disagree. The equations are about correlation, not causation. It is attractive to imagine ourselves in the driver's seat "causing"...
