reaction time of dollar falling between fingers

1. The problem statement, all variables and given/known data

If you are worried about safely driving after a party, I recommend you just not drive! But if you want to

see when you are finally okay to drive, here is a test to see if you are still too “impaired”. Take a dollar bill

and have a friend hold the bill from one of the short sides hanging straight down. Place your thumb and

forefinger opposite the bottom of the bill. Have your friend release the paper suddenly and try to catch it

with your thumb and forefinger. If you can catch this bill three times in a row, you are not too badly

impaired. Assuming the bill was falling freely without air resistance (not a bad assumption for the paper

falling sideways), calculate your reaction time. That is, how long does it take for the entire length of the

bill to fall between your fingers? (Use your hand to measure a dollar bill based on your body

measurements.)



i know that the acceleration is -9.8m/s²







2. Relevant equations

I was thinking of using d = v_it + 1/2at²



but i dont know d







3. The attempt at a solution



if i do know d am i choosing the right equation?