Solve the problem
-A rock is propelled upward from the top of a building 210 feet tall at an initial velocity of 176 feet per second. The function that describes the height of the rocket in terms of time $t$ is $s ( t ) = - 16 t ^ { 2 } + 176 t + 210$. Determine the time at which the rock reaches its maximum height.
A) $4.4 \mathrm { sec }$
B) $5.5 \mathrm { sec }$
C) $11 \mathrm { sec }$
D) $8.8 \mathrm { sec }$

Question

Quizplus · Accepted Answer

The maximum height is reached at the vertex of the parabola described by the function. The time at which this occurs is given by $ t = -\frac{b}{2a} $. Here, $ a = -16 $ and $ b = 176 $, so $ t = -\frac{176}{2(-16)} = 5.5 $ seconds.

Solve the Problem -A Rock Is Propelled Upward from the Top

Solve the Problem
-A Rock Is Propelled Upward from the Top