Recent content by Breston

The classical approximated formula describing frictional force is f = N\mu, directed oppositely to the motion direction. What about that kind of friction that arises when N is 0? How can I account of that? For example, suppose I let a cylinder fall inside a pipe nearly the same size, so that...

Cool, thank you both. By the way PEC is a perfect electric conductor, an idealized material with 0 resistivity.

Well, I still have some doubts. In the end, the formula for the energy dissipated during the process of discharging a capacitor is equal to the potential energy stored in the capacitor \frac{1}{2}Q_0V_0, which was actually quite obvious, since there's nothing else providing energy. My first...

Okay, thank you, the power dissipated by the resistor is IV = I^2R, then the integral had to be R\int_0^\infty e^{-\frac{2t}{RC}}dt which gives -\frac{R^2C}{2}[e^{-\frac{2t}{RC}}]^\infty_0 = \frac{R^2C}{2} [\frac{Vs}{A}] which is... dimensionally wrong? Edit: ok, by checking again everything I...

Hi there. I'm trying to evaluate the energy dissipated due to Joule effect on a resistor within an RC circuit (R, C, and battery in series), with the capacitor initially uncharged. Till now I just came up with the formula for the current flowing in the circuit i(t) = e^{-\frac{t}{RC}}, resulting...

Yeah, they move orthogonally, consider the two poles as a unique extended body. And yeah, I intended \vec{p}_f = m\vec{v}_f + 2M\vec{v}_t. I_O is pretty simple to calculate: \displaystyle I_O = 2\int_{0}^{L}l^2\frac{M}{L}dl = 2\frac{M}{L}\frac{L^3}{3} = \frac{2}{3}ML^2. Thanks everybody!

Ok I think I have a clear idea now. Please confirm my reasoning. The bind with the "floor" is not part of my system and therefore it produces an external force during the collision, binding the poles to the origin. If the collision lasts \Delta t, then, during the collision: \displaystyle...

Well, maybe I can apply laws of conservation of momentum. Considering the nature of the system (poles+particle), we can't state that linear momentum is conserved, since the poles are not free to translate, they can only rotate. I know I should consider angular momentum, but first please help me...

Hi there, right now I am making my first steps towards physics, and I would appreciate your help to solve some of my problems. As you surely have already noticed, I'm not english and I guarantee I'll make thousands of errors. Should I make any, please, try to always advise me, and if it's not...