SOLUTION: A person standing close to the edge on top of a 40 foot building throws a bal vertically upward. The quadratic function h(t)= -16t^2 +72t + 40 models the ball's height about the gr

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: A person standing close to the edge on top of a 40 foot building throws a bal vertically upward. The quadratic function h(t)= -16t^2 +72t + 40 models the ball's height about the gr      Log On


   

Question 1160555: A person standing close to the edge on top of a 40 foot building throws a bal vertically upward. The quadratic function h(t)= -16t^2 +72t + 40 models the ball's height about the ground, h(t), in feet, t seconds after it was thrown.
What is the maximum height of the ball?
How many seconds does it take until the ball hits the ground?
Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!


The maximum height is at the vertex of the parabola described by the quadratic function.

The vertex of

is at . For your height function, the maximum height is the -coordinate of the vertex point.

The height of the ball when it hits the ground is zero feet. Solve:



for the positive root.


John

My calculator said it, I believe it, that settles it