A projectile is thrown upward so that its distance above the ground after t seconds is $h = - 15 t ^ { 2 } + 660 t$ What is its maximum height?
A) 3630 ft
B) 5445 ft
C) 7260 ft
D) 10,890 ft

Question

Quizplus · Accepted Answer

The maximum height of a projectile described by the equation $h = -15t^2 + 660t$ can be found by using the vertex formula for a parabola, $t = -\frac{b}{2a}$, where $a = -15$ and $b = 660$. Plugging these values in gives $t = -\frac{660}{2(-15)} = 22$. Substituting $t = 22$ back into the original equation gives the maximum height: $h = -15(22)^2 + 660(22) = 7260$ ft.

A Projectile Is Thrown Upward So That Its Distance Above h=−15t2+660th = - 15 t ^ { 2 } + 660 th=−15t2+660t

A Projectile Is Thrown Upward So That Its Distance Above $h = - 15 t ^ { 2 } + 660 t$