SOLUTION: A ball is thrown into the air from a bridge that is 15 m above a river. The function that models the height, h(t), in metres , of the ball over time,t, in seconds is : h(t)=-4.9t^2

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: A ball is thrown into the air from a bridge that is 15 m above a river. The function that models the height, h(t), in metres , of the ball over time,t, in seconds is : h(t)=-4.9t^2      Log On


   

Question 831792: A ball is thrown into the air from a bridge that is 15 m above a river. The function that models the height, h(t), in metres , of the ball over time,t, in seconds is : h(t)=-4.9t^2+9t+15
When is the ball 17m above the water?
Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
17=-4.9t^2+9t+15
t = 0.258644
and
t = 1.57809