This is not strictly a physics problem, but I thought this would be the best place to ask... I am having trouble calculating the time between events using an acceleration formula. I have the rate of deceleration, and would like to know the time until the next full unit occurs. Code (Text): d = 1.0000000 cigarettes v = 0.0069444 cig/min a = -0.0000017 cig/min/min d = v*t + (a*t*t)/2 Am I using the right formula? Can anyone see a way to isolate time? Maybe suggest a variation on the formula that would have the effect I am looking for?