1. The problem statement, all variables and given/known data a balls inital velocity is 72 km/ph and falls 100 meters with gravity @ 10 meters per second and i need to work out the time it takes to fall to ground. i was given s=ut+0.5*gt^2 2. Relevant equations s=ut+0.5gt^2 v^2=u^2+2as t=(v-u)/a 3. The attempt at a solution v2=u2+2as v=squr u^2+2as v=squr 20^2+2*10*100 v=48.98979486 t=(v-u)/a t=(48.98979486-20)/10 t=2.898979486 seconds 100=20*2.898979486+0.5*10*2.898979486^2 is this correct?? and is there a way to do this with just the s=ut+0.5at^2 formula ?