Solve the problem.
-A person standing close to the edge on top of a 320-foot building throws a baseball vertically upward. The quadratic function s(t) = -16t2 + 64t + 320 models the ball's height above the ground, s(t), in feet, t seconds after it was thrown. After how many seconds does the ball reach its maximum height? Round to the nearest tenth of a second if necessary.
A) 2 seconds
B) 6.9 seconds
C) 384 seconds
D) 1.5 seconds

Question

Quizplus · Accepted Answer

The maximum height of a projectile in a quadratic equation of the form $s(t) = -16t^2 + 64t + 320$ is found at the vertex of the parabola. The time $t$ at which the maximum height occurs can be found using the formula $t = -\frac{b}{2a}$, where $a = -16$ and $b = 64$. Plugging these values in gives $t = -\frac{64}{2(-16)} = 2$ seconds.

Solve the Problem. -A Person Standing Close to the Edge on Top of on Top