Recent content by Isow

Hey, thanks, that was exactly what I needed! I realized the first boundary condition only set D=0, but I erroneously was thinking that the second boundary condition gave C=0 when, in fact, you're right: it gives k. I then applied the second initial condition in terms of absolute value, which I...

Homework Statement "Solve the wave equation with the following initial conditions and boundary conditions." ∂2Y/∂x2 = 1/v2 * ∂2Y/∂t2 Boundary conditions: ∂Y/∂x(x=0, t)=0 and Y(x=L,t)=0 Initial Conditions: ∂Y/∂t(x, t=0) = 0 Y(x,t=0) = δ(x-L/2) Homework Equations Using separation of...

The sign flip was a typo, and I did have 1/3 initially but fixed it so that probably explains the bug. The l^{2} term here actually ends up cancelling out when you divide through by the moment, l^{2}(m/3+M). I did absorb the 1/2 term into the b, which I hope is an okay liberty to take.

I think I've got it now, but for the drag I ended up integrating over the length of the rod: \int_{0}^{l}-br\theta'dr = -\frac{1}{2}bl^{2}\theta' Which seems right since it gives units of torque (the l^{2} term).

Okay, so it seems like you're saying Itotal = l2(m/3 + M) And we can sum the torques... so Ttotal = k1d12θ + k2d22θ + b*l*θ' ? I'm not sure about the drag part. I know the drag force is bθ', but converting that to torque by multiplying by l seems weird since it's not a point force, and would be...

Hey, thanks again. I wrote my last post right as you were posting. What you're calling the moment I'm calling the torque... but it seems like we're talking about the same thing. My understanding is that Torque = F*d and Fspring = kdθ so T = kd2θ. Why are you calling that the moment? Plus, the...

So I think I have the torque of the springs: T = k*d^2*θ When it comes to the mass, I'm not sure if I should be taking into account gravity, since equilibrium is at the horizontal. Would I just take into account the momentum of the mass working against the system, adding to drag? p = mv So...

Hi, thank you for the reply. The examples in my book all deal with a uniform rod and no mass attached, or the deal with a "massless" rod and mass. The former explicitly uses the CoM (l/2) to calculate torque and insert in my third equation. The latter are simple pendulums. So I have a free body...

Homework Statement A small ball with mass M attached to a uniform rod of mass m and length l pivoted at point o and attached to two springs with spring constant k1 and k2 at distance d1 and d2 from point o as shown in Fig 2. The system oscillates around the horizontal line. Assume the system...