H=+15 m v=+5 m/s Ball hits the ground when h(t)=-15m h(t)=-9.8t^2+vt+h => -15=-9.8t^2+5t+15 9.8t^2-5t-30=0 Solve for t, using quadratic formula, t=-1.513 or t=2.023 reject negative root due to context, so t=2.023 seconds
2) h(t)=-16t^2+20t+8 a. height before pitch is when t=0, or h(0)=8 b. highest point reached when h'(t)=-32t+20=0 => t=5/8 seconds c. highest point is t(5/8)=-16(5/8)^2+20(5/8)+8=47/5=9.4 m d. ball hits ground when h(t)=0 => solve t for h(t)=0 => t=-0.3187 seconds or t=1.569 seconds. Reject negative root to give time to hit ground = 1.569 since ball was pitched.
