Recent content by Thales

Thanks to both of you for the feedback. quarkman, if you want to learn about using latex, check out: Latex tomkeus, even if it's boring, I'd love to see it. :biggrin: I'm not sure if this forum provides an email attachment capability... But you can send it to...

I have this book, which provides the following torque equation for a rigid body: \sum\tau_{cg} = \frac{dL_{cg}}{dt} = I\frac{d\omega}{dt} + (\omega \times (I\omega)) Where L_{cg} is the angular momentum around the CG. The moments, inertia tensor, and angular velocity are all expressed...

Okay, I think I have figured this out. I apologize for thinking aloud on the board, but I'm always looking for feedback. :biggrin: Here is where I erred in my assessment of that experiment I posted above. Even though the spring force has the same velocity when let go, it doesn't...

I decided to run an experiment. I tied a mechanical pencil to a piece of yarn and hung it from a floor lamp. The yarn is about 27 inches long. The pencil was balanced at CM. I then have a device that delivers a pretty constant force all of the time, a stapler :smile: Anyway, I...

Thanks arildno, I very much appreciate your deeper insight here. I'm looking again at my equations, then are your equations. If I take your equations, and do the following -I_{1}=m\Delta v r\vec{j}\times(-I_{1}\vec{i})=\mathcal{I}\Delta\omega\vec{k} And, if I know the...

arildno, Many thanks :biggrin: Sorry for the late response. I've been having Internet troubles on this end, and haven't been able to respond. You have the problem exactly right. However, I have a question, which I assume is simple. How do you manipulate the cross...

I've been thinking about this, and I have another question, but this time with only a one point collision. I have a bit of a conundrum. If I have a thin rod with Mass M, and moment of inertia I, and the rod is hit by an impulse force at some distance r from its c.m., will the I get the...

Understood. This is what I gathered. :) Right, this is true. I was thinking that if I were to apply a frictional force, say at the wheels of an airplane, as it lands, this would be at right angles to the collision force. And, given that \mu_k = \frac{f}{F} \int...

It wasn't well presented. What I'm really trying to do is find the resultant linear and angular velocity components after impact. I know, at the outset, the velocities of each collision point before impact, as well as their points of impact. So, with a perfectly elastic collision, they...

Gza, I'm using the conservation of momentum, because I want the final velocities after collision. I realize it's general, but I want to find the general solution, presently. :smile: arildno, Good feedback! Right now I'm trying to follow my own line of thinking on this...

Hello, I am attempting to determine a two point collision response for a rigid body. One point collision I can calculate, but I can't seem to extend it to two points. So, I thought, maybe I could get some insight here. :) Set up (It'd be great to have the ability to draw this one...

Thanks Enigma. That definitely helped. Although I'm still trying to make sense out of the math for the product of inertia. I'd like to see how it was derived.

I'm wondering what the product of inertia is. What I mean is this, while I know the mathematical formula for it, I don't understand the underlying concept. For instance, I understand the moment of inertia, 'I', because I can relate it to the kinetic energy of rotation of a body. I also...