1. The problem statement, all variables and given/known data I am trying to calculate the estimated final velocity of a R/C hovercraft i am trying to built. The craft's weight is 6lbs and it is powered by a electric ducted fan that produces 21.3 ounces of thrust. Assuming this craft is actually hovering (no friction with the ground) and has an estimated drag coefficient of .8 (surface area of the front is .33m^2). Time is 6 minutes if needed (half of my battery). 2. Relevant equations F=ma a=f/m a=(Vf-Vo)/t 3. The attempt at a solution F=1bf=4.448N w=f=mg ----- 6lb=m(9.8) ( i am confused with my units) m=.816 a=F/M=4.448N/.816=5.39m/s^2 ??? I dont know where to go from here, I am just trying to estimate how fast (constant final velocity) i can get this to go on half my battery so that I know how far it will go before I need it to come back.