Chapter 8, Problem 2E

To determine

To find: The correct option.

Answer to Problem 2E

The correct option is G

Explanation of Solution

Given:

The velocity of the baseball is $105$ feet per second.

The height of the baseball initially is $5\text{ft}$ .

The height of the baseball $t$ seconds after begin thrown is given by the formula $h\left(t\right)=-16t^2+105t+5$ .

Calculation:

Consider the expression for the height of the ball is,

  $h\left(t\right)=-16t^2+105t+5$

Differentiate the equation with respect to $x$ ,

  $\begin{array}{c}\frac{dy}{dt}=-2\left(16\right)t+105\\ =-32t+105\end{array}$

To obtain the value of $t$ substitute $0$ for $\frac{dy}{dx}$ in the above equation.

  $\begin{array}{l}0=-32t+105\\ t=3.28\text{sec}\end{array}$

The correct option is G