SOLUTION: A projectile on Earth is fired straight upward so that its distance (in feet) above the ground t seconds after firing is given by s (t) = 16t² + 400t Find the maximum height it re

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: A projectile on Earth is fired straight upward so that its distance (in feet) above the ground t seconds after firing is given by s (t) = 16t² + 400t Find the maximum height it re      Log On

Hi

s (t) = -16t^ + 400t    |s' = -32t + 400, t = 12.5

      = -16(t - 400/32)^2) + 2500  |Completing Square

      = -16(t - 12.5)^2) + 2500

Hmax = 2500ft in 12.5sec