Recent content by jds17

Thanks! I know, the angle is dimensionless, but still the energy cannot depend on the angle. I just found why I could not continue with the calculation: I left the radius r in the expression for the energy, but I need to expand it in terms of r_0, theta and the eccentricity as well! It is...

Hi, I love the lectures by David Tong. Usually I can follow his calculations (but I am not yet so far into the lectures...). But one that I just cannot do is the derivation of the energy in (4.16), the expression being ##E = \frac {mk^2} {2 l^2} (e^2 - 1)##, where l is the constant angular...

Thank you for your reply! Since the rolling object only touches the surface in one point, I don't see why the curvature should play a role for the magnitude of the static friction, which is modeled as being opposed to the motion and having maximum value ##\mu N##, where ##N## is the magnitude...

There is a nice problem in Taylor: Classical Mechanics of a puck sliding without friction down a sphere in a uniform gravitational field (problem 4.8). The question there was at which height the puck takes off from the sphere, which is not hard to solve using conservation of energy. This...

Hi, everything turned out nicely, considering a partition into concentric hollow cylinders, adding their M.I.s (calculated as before) up and going to the limit gives the answer in table 19-2!

@Doc Al: Thank you for your reply, I took the cylinder as a hollow one, and this seems to be my mistake. I will try to do the calculation again for the solid cylinder as soon as I get back home. @K^2: thank you, too, but I wanted to find out what was wrong with my thinking instead of doing a...

Hi, I am working through the Feynman lectures on physics and trying to calculate the moment of inertia stated in the title. (the taxis of rotation going through c.m., orthogonal to length). My approach is to slice the cylinder into thin rods along the length, using the parallel taxis theorem...