1. The problem statement, all variables and given/known data A ball thrown horizontally at 12.4m/s from the roof of a building lands 20.2m from the base of the building. How tall is the building? 2. Relevant equations I think I'm supposed to use these: horizontal motion: x=x0+vx0t vertical motion: y=y0=+vy0(t)-.5at^2 3. The attempt at a solution So this is what I think goes where: x=20.2 x0= 0 y0= 0 vy0=12.4 a= -9.8 I plugged them in but I'm not sure if they're even in the right spot. After I plug them in I have no idea where to go from there. Please help.