🔒 Locked

Adding angular velocities

Started by okonomiyaki Jul 31, 2006 at 3:08 PM 1 replies 1.8k views

Original Post

Jul 31, 2006 at 3:08 PM

Angular movement seems to be discussed a lot here (a search brings up quite a bit), so I apologize if this is a common question. I couldn't quite get a clear answer from other posts or google. I'm implementing some VERY simple movements to my system: Linear and angular velocities. The angular velocity is represented by a 3d vector representing the axis of rotation, and angle being the length of the vector (this is common). You can probably answer this with one word: is it OK to add angular velocities as I do with linear velocities? I have AddVelocity() functions, and I just want to make sure it's ok to add the angular velocity vectors (representing some kind of force pushing the object to gain velocity). This is physically and mathematically correct, right? Visually it makes sense.

taby

1,513

taby

Jul 31, 2006 at 7:51 PM

You are correct. Summing angular velocities is as legitimate as summing linear velocities.

Example:
A body spins at 2PI/sec. It is accelerated by enough force to gain an additional velocity of 2PI/sec. The body now spins at a rate of 4PI/sec.

Of course, most bodies are not single particles, but systems of many. What is closer to the axis of rotation has a lower level of angular momentum versus what is further away from it.

Example:
I spin around at 4PI/sec. Because my heart is closer to my axis of rotation than what my extended hands would be, it covers less distance in space, and therefore requires less momentum to travel the global constant rate in time of 4PI/sec.

Now knowing the difference between the two only makes me think "if only I knew then what I know now". I guess life would suck if one were to truly know it all anyway. :)

okonomiyaki

Author

okonomiyaki

Jul 31, 2006 at 10:04 PM

Thanks!

Quote:

Of course, most bodies are not single particles, but systems of many. What is closer to the axis of rotation has a lower level of angular momentum versus what is further away from it.

Don't you mean linear momentum?

Edit: no, you are right, I was confusing velocity and momentum. Thanks for the tip.

Topic Locked

This topic has been locked by a moderator. New replies are not allowed.