Chapter 9.3, Problem 3P

Solution

(a)

To calculate: The width of the tank.

The required width is 13 ft.

Given Information:

The given height of the tank is 4 ft and the volume is $500{\text{ft}}^3$ .

Formula Used:

Volume of a cylinder is $\pi r^{2}h$ .

Calculation:

It is given that the height of the tank is 4 ft and the volume is $500{\text{ft}}^3$ .

Now, find the width. Use the formula $\pi r^{2}h$ .

  $\begin{array}{c}\pi r^2\times 4=500\\ \frac{22}{7}\times r^2\times 4=500\\ r^2=\frac{500\times 7}{4\times 22}\\ r\approx 6.30\end{array}$

Thus, the width is,

  $\begin{array}{c}\text{width}=2\times 6.30\\ =12.6\text{ft}\end{array}$

Convert nearest to the tenth foot.

  $\text{width}=13\text{ft}$

Hence, the required width is 13 ft.

(b)

To find: The disadvantages of using a graph to approximate the solution.

The disadvantages of using a graph to approximate the solution is less accurate value for the fractions.

Explanation:

In graph it is very difficult to find the fractional points.

Thus, the solution can be different from the actual solution.

Hence, the disadvantages of using a graph to approximate the solution is less accurate value for the fractions.