- #1
eterna2
- 2
- 0
Hi! I would be extremely grateful if anyone could help me figure out this mess... I hadn't touched mechanics for too many years and I guessed i gotten myself a little confused...
I am trying to model a 3D needle/object in a virtual world... I have done the part on freebodies collision... but i think i am starting to get everything mixed up...
I am now trying to model a free hanging needle which hangs from a thread, and the needle is suppose to response to other objects. What i did previously was a zero gee free body needle, which can be manipulated by other objects...
now with addition of gravity and a reaction force from a thread confused me, because in the prev part, I made use of impulses to calculate and model the resultant responses... What i did was to just compute the resultant orientation and position of the needle, with respect to its center of mass, as in i pretend the needle is a point mass.
So now the problem I am facing is tat, for a free hanging needle in an initially unstable elevated level, the resultant force at the CM is 0, and I can get the resultant moment. I can calculate the position of the CM in the next time step, by finding the acceleration at CM, but I have no idea how can i compute the orientation of the needle at the next time step?
Can I:
Summation of Moments = Moment of Inertia x alpha
so i can find:
alpha
so
Angular velocity = initial angular velocity + alpha
? so assuming i am rite,
how can i integrate this with impulses? as in a object hitting the free hanging needle...
cuz for my free body collision,
Angular velocity = inverse of moment of inertia x angular momentum
so which one shld i use to find the angular velocity of the needle so tat i can compute its orientation in the next time step??
thanks :)
I am trying to model a 3D needle/object in a virtual world... I have done the part on freebodies collision... but i think i am starting to get everything mixed up...
I am now trying to model a free hanging needle which hangs from a thread, and the needle is suppose to response to other objects. What i did previously was a zero gee free body needle, which can be manipulated by other objects...
now with addition of gravity and a reaction force from a thread confused me, because in the prev part, I made use of impulses to calculate and model the resultant responses... What i did was to just compute the resultant orientation and position of the needle, with respect to its center of mass, as in i pretend the needle is a point mass.
So now the problem I am facing is tat, for a free hanging needle in an initially unstable elevated level, the resultant force at the CM is 0, and I can get the resultant moment. I can calculate the position of the CM in the next time step, by finding the acceleration at CM, but I have no idea how can i compute the orientation of the needle at the next time step?
Can I:
Summation of Moments = Moment of Inertia x alpha
so i can find:
alpha
so
Angular velocity = initial angular velocity + alpha
? so assuming i am rite,
how can i integrate this with impulses? as in a object hitting the free hanging needle...
cuz for my free body collision,
Angular velocity = inverse of moment of inertia x angular momentum
so which one shld i use to find the angular velocity of the needle so tat i can compute its orientation in the next time step??
thanks :)