Recent content by anotherghost

Homework Statement You're given a hoop with mass m and radius R balanced on top of a knife blade. (The diagram looks like a triangle with a circle balanced on the tip.) Find the period of small oscillations. (Yes, that is all the problem says.) Homework Equations Moment of inertia of a...

Note: I have the idea of using the equipartition theorem, and the numbers come out right, but I'm worried about two things. First, I think the prof said that we weren't supposed to need to know anything aside from what was written on the assignment, and the mass of sodium is not written on the...

Homework Statement A doppler effect problem: A sodium atom is emitting radiation at a wavelength of 6000 angstroms. When measured however the wavelength is widened to 6000 +/- 0.02 angstams. If this is primarily due to the doppler effect, what is the temperature of the sodium atom...

The problem: You are given the problem of analyzing the dynamics of a line of cars moving on a one-lane highway. One approach to this problem is to assume that the line of cars behaves like a group of coupled oscillators. How would you set this problem up in a tractable way? Make lots of...

Oh man, duh. I can't believe I didn't see that. I can get the rest of it if I have that a no problem. Guess I'll just have to chalk that one up to a brain fart, hope I'll still get partial credit. :)

Homework Statement You've got two masses, m1 and m2, hanging from opposite ends of a rope that goes over a pulley with radius R. Both the masses are suspended by the rope alone and the pulley is on a frictionless peg. M2 moves down by x2 meters in 5 seconds. I believe that's all the...

So, I'm interested in the big questions. I guess that leads me towards cosmology - though, quantum or particle physics, or string theory are also tied to the stuff that I want to find out. I'm doing my BS in physics right now and I'm trying to figure out where I want to go for the PhD. I...

Homework Statement So you've got two people standing on a boat, everything at rest, and the masses of both people as well as the boat are known. Let's call them Richard and Sandra, so the variables are Mr (mass of Richard), Ms (mass of Sandra), and Mb (mass of boat). When one of these...

Homework Statement All right, so: dog on a boat. It's the snoopy problem. There's a boat floating on some water, and there's a dog on the end - he starts at X away from the shore. Then, he walks a length L across the boat towards the shore. How far is he away from the shore at the end...

Quick question: I'm having trouble understanding a concept: say you've got a mass hanging from a peg by a string. Using conservation of energy, you can figure out what the minimum velocity is that the mass has to have initially so that it goes around the circle: at the top, mv^2/r = mg, so...