After how many seconds does the ball reach maximum height?

Question

A person standing close to  edge on the top of a 200-foot building throws a baseball vertically upward. The quadratic function s(t)=-16t^2+64+200 models the balls height above the ground, s(t), in feet, t seconds after it was thrown

Answer 1

s(t)=-16t^2+64t +200

 

The time t to reach the maximum height is obtained by finding the axis of symmetry for the quadratic equation.

 

t = - b/2a.

 

Substitute and simplify.