i need a proof/solution to this question. please help. if a ball is trown vertically upward at 80 ft/sec it will continue to rise for approximately how many seconds? how many seconds will the ball return to the ground? thanks!

v(t) = v(0) + (g/2)t

Where g ≈ -32.174 ft/s^2

At the peak of the trajectory: v(t)=0
Solve for t, given v(0)=80 ft/sec