1. The problem statement, all variables and given/known data It is desired to have a pile driver strike a pile with a speed of 20 m/s. Assuming the driver to be in free fall, from how high above the pile should be released? 2. Relevant equations Used v^(2) = V(o)^(2) + 2ax v=final velocity V(o) =initial velocity a=acceleration x=position 3. The attempt at a solution I set up my problem as (20 m/s)^(2) = (0m/s)^(2) +2(-9.8 m/s^(2))x finding position (x). Next step looks like this 400 m/s^(2) = -19.6 m/s^(2) (x) Last step looks like (400 m/s^(2))/(-19.6 m/s^(2)) = x Answer: -20.4 = x Answer is negative and units are wrong. I believe all the units would cancel out and the answer would be unitless. I was also thinking about using the equation x=V(o)T + 1/2at^(2) but problem is I wasn't given a time unless I assume time to be 0. Please Help, Thank You.