rotation crap =(

i’m trying to rotate a torus such that is accelerates to a maximum angular velocity and deccelerates to a velocity of 0 AND a rotation angle of 0 degrees. however, i am having trouble finding out the angular decceleration value the ring should have. my question: how would i figure out the decceleration of the ring given current angular velocity and decceleration time? i have tried some formulas but i think i’m doing something wrong because it’s not working =( thanks in advance

You may have the right forumlae, but round off error can contribute to an erroneous conclusion.

This question would be better taken up in a physics/physics programming forum.