Chapter 8.4, Problem 9CYU

(a)

To determine

The initial height of the discus.

Answer to Problem 9CYU

  $h=6\text{feet}$

Explanation of Solution

Given:

The given polynomial is:

  $h=-16t^2+95t+6$

Calculation:

For initial height, put t = 0,

  $\begin{array}{l}h=-16t^2+95t+6\\ h=-16{\left(0\right)}^2+95\left(0\right)+6\\ h=0+0+6\\ h=6\text{feet}\end{array}$

(b)

To determine

The time at which the discus will hit the ground.

Answer to Problem 9CYU

  $t=6\text{seconds}$

Explanation of Solution

Given:

The given polynomial is:

  $h=-16t^2+95t+6$

Calculation:

The time, at which the discus will hit the ground, the height will become zero.

  $\begin{array}{l}h=-16t^2+95t+6\\ 0=16t^2-95t-6\\ 0=16t^2-96t+t-6\\ 0=\left(16t+1\right)\left(t-6\right)\\ t=-\frac{1}{6},6\\ \text{time cannot be negative}\text{. Therefore,}\\ t=6\text{seconds}\end{array}$