Solve the problem.
-A projectile is thrown upward so that its distance above the ground after $\mathrm { t }$ seconds is $\mathrm { h } = - 13 \mathrm { t } ^ { 2 } + 364 \mathrm { t }$. After how many seconds does it reach its maximum height?
A) $14 \mathrm {~s}$
B) $28 \mathrm {~s}$
C) $21 \mathrm {~s}$
D) $7 \mathrm {~s}$

Question

Quizplus · Accepted Answer

The maximum height is reached at the vertex of the parabola represented by the equation $h = -13t^2 + 364t$. The time $t$ at the vertex can be found using the formula $t = -\frac{b}{2a}$, where $a = -13$ and $b = 364$. Substituting these values gives $t = -\frac{364}{2(-13)} = 14$.

Solve the Problem t\mathrm { t }t Seconds Is h=−13t2+364t\mathrm { h } = - 13 \mathrm { t } ^ { 2 } + 364 \mathrm { t }h=−13t2+364t

Solve the Problem $\mathrm { t }$ Seconds Is $\mathrm { h } = - 13 \mathrm { t } ^ { 2 } + 364 \mathrm { t }$