Recent content by Roboticist

One last question. So the equation I now have is: E(t) = (1/2)m(Ldø/dt)^2 + mgL(1-cosø) But this is the equation of energy for a pendulum, not a damped pendulum, right? So would the equation of energy for a pendulum where energy is constantly being taken out of the system be: E(t) =...

All right. s = rø ds/dt = rdø/dt ds = rdø dø = (1/r)ds v = ds/dt = rdø/dt ?

Is my problem converting angular velocity into linear velocity? Because dø/dt itself is angular velocity. The only thing I can find is people using conservation of energy to solve for the velocity v. Of course, if I did that my equations would just cancel out.

Ah I'm meeting with my professor at 1:30...I'm running out of time to get this energy equation right. 1) Awesome. 2) Sweetness. 3)http://www.kettering.edu/~drussell/Demos/Pendulum/Pendulum.gif cosø = h/L --> h = L - Lcosø. --> L(1-cosø) 4) I'm really not certain. It's not x(t) =...

Yes, all I am trying to do is develop equations for E(t) and E'(t). I am not able to make small angle approximations, and while I know that I will not actually be able to solve the second order differential equation, I just want to set up the equations correctly and then go as far as I can.

Maybe I've been on the wrong track. After all, KE + PE = Total E. So I shouldn't be adding a new term, but subtracting from a current one. I'm thinking that this resistive force, air resistance/random frictions in reality but that's unimportant in our theoretical model, must be subtracting...

1. Yes, I believe the energy of a damped pendulum will have additional contributions to the total energy of the system. I define cø' as some damping force proportional to angular velocity (ø'). C is simply a constant. I suppose its units would then have to be kg/s. Therefore, this force would do...

This may straddle more advanced physics, but I thought it leaned toward introductory. Homework Statement I have been told to find the net energy of a damped pendulum. Homework Equations Obviously the equation of energy for an undamped pendulum is just: E = KE + PE = .5mv^2 + mgh = 0 I...