Recent content by rc75

In section 4 of Landau and Lifgarbagez they derive the expression for the kinetic energy by expanding the Lagrangian around v+e. The resulting expression has a term which must be a total time derivative so that the equations of motion are unaffected. The text claims that the term dL/d(v^2) v.e...

Falling Chimney Solution I've got a solution to this problem now that matches the solution given by the problem statement, but I use a different approach than the one I used above. Now I start by writing down the total angular momentum of the chimney as the angular momentum of part of the...

I'm having trouble with solving this problem: Suppose we have a cylindrical brick chimney with height L. It starts to topple over, rotating rigidly about its base until it breaks. Show that it is most likely to break a distance L/3 from the base because the torque is too great. So I'm...

Never mind. I made a really stupid mistake in simplifying after making the substitutions. I get the same result as the solutions now. And to get z<<R you have to set up an effective potential and set it equal to zero.

I don't think it's necessary to deal with the forces. Since we know the angular velocity of the particle at the equator of the sphere, we know its initial energy which we can equate to a general expression for the energy of the particle. \frac{m}{2}[ \dot{\rho}^2 + \rho ^2 \dot{\phi}^2...

I'm trying to solve a problem from the book of qualifier problems by Cahn, but I don't see how he got his solution. The problem is about a particle constrained to move on a smooth spherical surface with radius R. The particle starts at the equator of the sphere with an angular velocity of...