Recent content by TSny
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Some work on MTW Figure 25.7
For online calculation of the incomplete elliptic integral ##F[\phi, m]##, where ##m = k^2##, see this site at WolframAlpha. The link shows the calculation of ##F[0.3, 0.8]##.- TSny
- Post #6
- Forum: Advanced Physics Homework Help
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Some work on MTW Figure 25.7
I don't see much difference between the MTW (Darwin) calculations and your calculations using ##r_1, r_2, ## and ##r_3##. Darwin shows how the three roots can be expressed in terms of just ##R##, the distance of closest approach. (See post #2). The expressions used in MTW are easily shown to...- TSny
- Post #4
- Forum: Advanced Physics Homework Help
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Some work on MTW Figure 25.7
The relations between the three root ##(r_1, r_2, r_3)## and the quantities ##R## and ##Q## are given in the paper by C. Darwin referenced in Fig. 25.7 of MTW. You can read this paper online here if you register for a free account. Section 8 of the paper deals with the orbits of light rays...- TSny
- Post #2
- Forum: Advanced Physics Homework Help
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Graduate Another derivation from Quantum Fields on curved spacetime
From ##t = \alpha \sinh(\tau/\alpha)##, we have ##z = (t^2 + \alpha^2)^{1/2} = \alpha \cosh(\tau/\alpha)##. Use these to express the denominator of (3.59) in terms of ##\tau## and ##\tau'##. Note ##\mathbf x = z## and ##\mathbf x' = z'##. Using identities for the hyperbolic sine and cosine...- TSny
- Post #2
- Forum: Special and General Relativity
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A rocket and the Coriolis acceleration
Yes, the Coriolis force is toward the right. In the video below, you can see that when the rotating frame rotates counterclockwise relative to the inertial frame of the room, the ball deflects "toward the right" relative to the person tossing the ball. So, the direction of the Coriolis force is...- TSny
- Post #25
- Forum: Advanced Physics Homework Help
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A rocket and the Coriolis acceleration
Yes, I agree that the x-axis as drawn is bad. The x-axis (toward the east) should be into the page (perpendicular to the y-z plane). The angle ##\lambda## should be the angle between the equatorial plane of the earth and the z-axis, not the angle between the x and z axes. But the mathematical...- TSny
- Post #10
- Forum: Advanced Physics Homework Help
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A rocket and the Coriolis acceleration
Your work looks correct to me (except, as pointed out by @kuruman, ##m## should not be in your expression for the acceleration). I agree with your answer of west.- TSny
- Post #8
- Forum: Advanced Physics Homework Help
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Electric potential due to shell containing a charge at an offset outside
Looks good. Recall @haruspex 's comment: If the charge, ##-q##, on the inner surface were uniformly spread, what would the potential at ##A## be due to this charge? Does it matter that the charge is actually not uniformly spread?- TSny
- Post #6
- Forum: Introductory Physics Homework Help
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Undergrad Identification of changes in internal energy with work (in Callen's Thermodynamics)
I'm not familiar with any treatments of thermodynamics that prove differentiability of ##U##. I think physicists tend not to worry too much about it. They just assume differentiability. For example, regarding entropy, Callen gives on page 28: So, Callen postulates differentiability of ##S##.- TSny
- Post #6
- Forum: Thermodynamics
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Undergrad Identification of changes in internal energy with work (in Callen's Thermodynamics)
Even though we need quantum mechanics to describe atoms, we still assume that systems of atoms have well-defined energies and that the law of conservation of energy is valid. On page 17 of Callen, we read When work is done on an adiabatically enclosed system, we can imagine it being performed...- TSny
- Post #4
- Forum: Thermodynamics
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Undergrad Identification of changes in internal energy with work (in Callen's Thermodynamics)
I think Callen’s conclusion follows from his discussions earlier in Chapter 1. The change in the internal energy of a system during a process equals the net amount of energy transferred to the system during the process. This follows from the principle of conservation of energy. For simple...- TSny
- Post #2
- Forum: Thermodynamics
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A different periodic table to ponder
You can read a discription for the chart here. Click on the picture and zoom in. -
Undergrad How do I stretch a laser from a beam into a sheet?
I don't know. A highly reflective metal surface or mirror would not absorb very much. Each ray of light in the beam obeys the law of reflection at the curved surface. -
Undergrad How do I stretch a laser from a beam into a sheet?
You might experiment with fanning out the beam by reflecting off a smooth cylindrical surface. Here, I used a ceramic mug. -
Chain falling out of a horizontal tube onto a table
Very good. I'm glad I could help.- TSny
- Post #82
- Forum: Introductory Physics Homework Help