1. The problem statement, all variables and given/known data Human reaction time is usually about .20s. If your lab partner holds a ruler between your fingers and thumb and releases it without warning, how far can you expect the ruler to fall before you catch it. (disregard air resistance g= 9.81 m/s^2) 2. Relevant equations not sure what to use. 3. The attempt at a solution I was thinking on using velocity? but I don't know, I don't think I have much info. the answer is 19.6 cm if anyone could please help me, set this up... I would truly appreicate it.