# Recent content by cameo_demon

1. ### Quantum Mechanics - Supplemental text?

Quantum Mechanics -- Supplemental text? Hello, I'm currently in a quantum mechanics class (undergraduate) that is using Griffiths Intro to Quantum Mechanics (second edition). I've taken solid state physics, electromagnetism, thermodynamics and statistical mechanics, among other physics...

1) no grad students/ta's at my school. small liberal arts college in the northeast, vassar college. 2) my grades have actually gone up since freshmen year, but stayed at a constant B+ even with significantly increased effort. 3) it's not about failing the classes, it's that i probably...

hi all. i'm a junior physics major and i recently have felt like i've hit the total burnout stage of being a physics major. for my electromagnetism class i spend between 20 and 30 hours per week outside of class on the homework (usually 5 or more problems from griffiths) plus reading (with...
4. ### Packing fraction of body-centered cubic lattice - solid state physics

packing fraction of body-centered cubic lattice -- solid state physics Homework Statement This is part of a series of short questions (i.e. prove everything in Kittel Ch. 1, Table 2): Prove that the packing fraction of a BCC (body-centered) cubic lattice is: 1/8 * pi * \sqrt{3}...
5. ### Coriolis Effect with Friction

The following problem is take from Thorton and Marion's Classical Dynamics, 5th edition, p. 408, chapter 10, problem 3. Given A puck of mass m on a merry-go-round (a flat rotating disk) has constant angular velocity \omega and coefficient of static friction between the puck and the disk of...
6. ### Force on Particle in Dust Cloud

Yes I think that makes more sense. Thanks for your help!
7. ### Force on Particle in Dust Cloud

Ah, alright! So the mass of the dust cloud (as far as we are concerned, which is the radius of the particle) is now: M_{2} = \frac{4}{3} \pi\rho_{2} (r-R_{1})^{3} F = \frac{4}{3} \frac{Gm \pi ({R_{1}}^{3}\rho_{1} + (r - R_{1})^{3}\rho_{2})}{r^{2}} and I'm assuming there should be a few...
8. ### Force on Particle in Dust Cloud

[SOLVED] Force on Particle in Dust Cloud The following problem is from Thorton & Marion's Classical Dynamics, Ch. 5 Problem 5-13 (p. 205 in the 5th edition of the text) Homework Statement A planet of density \rho_{1} (spherical core, radius R_{1}) with a thick spherical cloud of dust (density...
9. ### Projectile Fired Up A Hill

the following problem is from the 5th edition of Thorton and Marion's "Classical Dynamics" ch.2 problem 14 p.92 Homework Statement A projectile is fired with initial speed v_0 at an elevation angle of alpha up a hill of slope beta (alpha > beta). (a) how far up the hill will the...
10. ### Classical Mechanics Dynamic Drag Resistance

ah so using the equation for a i can sub it into a = dv/dt and just solve the differential equation, same deal for position once i find the velocity equation. easy enough, thanks!
11. ### Classical Mechanics Dynamic Drag Resistance

for the next part of the problem, we're asked: at t=5 sec, find v and x again, mg - kmv^2 = ma, but this time a does not equal zero, solving for a, a=g-kv^2 to find x and v, can i plug in the terminal velocity as v_final and solve using standard kinematic equations, or do i need to solve a...
12. ### Classical Mechanics Dynamic Drag Resistance

well see the follow up to that question is that major leaguers throw around 90 to 100mph often enough, and so the professor asks if there is a contradiction. my conjecture is that the spin often applied to the ball would give it additional momentum, and that a dead spinless ball would only top...
13. ### Classical Mechanics Dynamic Drag Resistance

a diagram he attached just shoes it moving in the downward y direction, without a given height. as it falls gravity is acting on the ball so we have mg and then with drag acting against it, given here as kmv^2, we have mg - kmv^2 = ma = 0 for the terminal velocity. then setting mg = kmv^2...
14. ### Classical Mechanics Dynamic Drag Resistance

this problem is one just made up by my professor, and isn't in the thorton and marion book. is terminal velocity at a=0?
15. ### Classical Mechanics Dynamic Drag Resistance

i'm not even sure where to get started with this one because the thorton and marion classical dynamics book is really awful. BEGIN PROBLEM Suppose a baseball, which has a mass of 150 g and a diameter D of 7 cm is released from rest. For a sphere in air, the dynamic drag is F_d=.25 D^2 V^2...