PeterDonis, thank you! Your explanation was succinct, complete,and very helpful. It's posts like yours that make this forum such a valuable resource.
I now have a better understanding of the differences between classical and general relativistic inertial frames. After your explanation, it...
I'm reviewing physics after ~30yrs of neglect, starting with Halliday & Resnick (and the internet).
Here's what I understand to be standard Newtonian/classical inertial frames:
1. There exists a set of reference frames, called inertial frames, in which mass, time, force, acceleration, etc. are...
Thank you for your helpful responses, let me modify my OP.
Since a simple harmonic oscillator is a conservative system with no energy losses, then an undamped harmonic oscillator driven at a frequency other than the system's natural frequency can't be receiving any net energy from the driving...
This isn't homework. I'm reviewing physics after many years of neglect.
Since a simple harmonic oscillator is a conservative system with no energy losses, then a driven undamped harmonic oscillator, once the transient solution has died out, can't be receiving any energy from the driving...
Please refer to the OP. I didn't make up this problem.
From the OP:
Ex. 2. Halliday & Resnick, 4th ed., ch.9, problem 55. "To keep a conveyor belt moving when it transports luggage requires a greater driving force than for an empty belt. What additional driving force is needed if the belt...
No. The mass that falls off has no horiz. mom. It is stopped by the wall.
No. At the end of the belt, the wall pushes on the mass, stopping it. As the mass stops, the mass pushes with friction on the belt and the belt pushes back on the mass. This is F_{out} and F_{out}\neq0. Once the mass has...
I've talked to a few people and made progress.
Ignore Ex. 1. The rocket eqn. (1) is derived for systems in which the exhaust and the rocket (the total closed system, if you will) are affected by exactly the same external forces. But in Ex. 1, whether one considers the pile to be the rocket...
Sorry, but this will be a long post.
This isn't homework, I'm reviewing physics after many years of neglect.
Halliday & Resnick, 4th Ed., section on variable mass and rockets, refers the interested reader to an article, "Force, Momentum Change, and Motion," Martin S. Tiersten, Am. J...
This isn't homework. I'm reviewing physics after many years of neglect. As with most of my posts, I made this problem up.
Let object A have mass m_A and object B have mass m_B. One of A's surfaces is flat, as is one of B's. These flat surfaces are in contact and slide relative to each other...
Thx for the helpful responses.
It now seems clear to me that, since rigid rods do not exist, the rod's strain determines its tension or compression, leaving 2 equations (sum of forces on the masses) and the 2 unknown static frictions.
In other words, if the angle in the ramp is small...
This isn't homework...I'm reviewing physics after many years of neglect.
Given 2 masses, m_1, m_2, connected by a rigid, massless rod, stationary with respect to a ramp which makes an angle of \theta with the horizontal, with coefficients of static friction between the masses and the ramp =...
I guess I'm trying to convince myself that it's not always possible to find a function, f(x), such that \small f_{x}(x(t)) = (\frac{dx}{dt})^2. I wish I could think of a simple straightforward way of showing that.
This isn't homework. I'm reviewing calculus and basic physics after many years of neglect.
I want to show that a damped harmonic oscillator in one dimension is nonconservative. Given F = -kx - \small\muv, if F were conservative then there would exist P(x) such that \small -\frac{dP}{dx} = F...
outermeasure at http://www.sosmath.com/CBB/viewtopic.php?f=3&t=58677 explained it simply:
Seems obvious now. Rotate to be able to integrate both of the iterated integrals with antiderivatives of elementary functions rather than power series. I should have seen that. :)