How do I find the acceleration of an object at a certain velocity if I know it's mass and terminal velocity? [closed]

I have a mass of 85kg and a terminal velocity of 46.7m/s. I think I correctly calculated the coefficient of air resistance(b) as 17.84 because I know that the Resistance force at terminal velocity is 833.13 = b($v_t$). I need to figure the acceleration of the object when it is traveling at 30m/s and what the drag force would be at that point as well. R=bv doesn't seem to work at that point, so my b must be off which doesn't really make sense to me.

-

closed as too localized by David Z♦Sep 30 '11 at 0:41

This question is unlikely to help any future visitors; it is only relevant to a small geographic area, a specific moment in time, or an extraordinarily narrow situation that is not generally applicable to the worldwide audience of the internet. For help making this question more broadly applicable, visit the help center.If this question can be reworded to fit the rules in the help center, please edit the question.

Hi Michael, welcome to Physics Stack Exchange! This is not a homework help site, but rather a Q&A site for general conceptual questions about physics; the way you've written your question, it's really specific to your particular problem. If the problem you're having with your question is related to not understanding some concept of physics, perhaps it can be edited to make it more appropriate here, but we'd need to know more about the trouble you're having than just that you're not getting the right answer. – David Z Sep 30 '11 at 0:47