ball drops 45m under g=10m/s/s
45=1/2x10xt^2 ... application of kinematic equaion from rest
90/10=t^2
t=3
24.0 m in 3 secs => 8m/s no air resistance
4 N/cm^2 is the answer. the way you get this is the formula for pressure is P=F/A. So you would plug in the numbers which would make the equation P=12/3 which you know equals 4. The units for pressure is N/cm^2 or N/m^2
I hope this helps
