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am i on the right track?

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If you have a two rigid bodies with a bar between them that links them together (a pin joint) than your physics should still be simple. If a force is applied to one of the objects, then the mass that is accelerated along the vector of the bar is the sum of the masses of the 2 objects (lets assume a weightless bar for now) however... the mass that is accelerated in the direction perpendicular to the bar''s vector is just the mass upon which the force is applied. Try it out on paper... connect two balls (in outter space perhaps) with this "pin joint bar" & apply a force on one of the balls at an angle that is 45 degrees to the bar''s vector. For every iteration following, you must take into account each of the ball''s velocity vectors (really their momentum vectors are of interest) & again... the momentum of each object along the vector of the bar must be calculated using the total mass of the two objects, however the momentum of each object along the vector perpendicular to the bar vector should be calculated with each of the respective object''s mass only, not both.

I hope that was clear as mud.

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i kind of see what you're getting at with the bar.
i'm trying to find a way that i can keep my existing physics for the rigid bodies as they are, and add in forces or mass to compensate. I'm coming back to the idea below, that i should bring in forces that compensate for the extra mass:

say i have a pin joint and am applying the force directly along the vector of the bar, to the first mass (actually a rigid body, not a point mass) as you describe.
in order to get the second mass to move as if it were connected by the bar, i can either i can apply the same force to the second body and change the masses of both objects OR
apply a force to both the second body in the direction of the initial force as well as another force in the opposite direction to the first body, leaving both rigid bodies with the same mass.
ie: if both bodies were of the same mass, i'd end up with this:

----->F(B1)<-----F/2 XXXXBARXXX F/2------->(B2)

i think this would keep motion correct for forces applied perpindicular to the bar, as a dot product will reduce this to zero (edit: for the second mass).
does that make sense? would it work?

[edited by - coke_baby on March 30, 2004 2:35:41 PM]

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