Chapter 8.4, Problem 60HP

To determine

The actual wingspan if the scale is $5\text{ centimeters}=2\text{ meters}$ .

Answer to Problem 60HP

  $\text{11}\text{.4 meters}$

Explanation of Solution

Given information:

The model’s wingspan is 28.5 centimeters.

Concept Used:

Rules of Addition/ Subtraction:

• Two numbers with similar sign always get added and the resulting number will carry the similar sign.
• Two numbers with opposite signs always get subtracted and the resulting number will carry the sign of larger number.

Rules of Multiplication/ Division:

• The product/quotient of two similar sign numbers is always positive.
• The product/quotient of two numbers with opposite signs is always negative.

Calculation:

In order to find the length of actual wingspan, use the unitary method with the given scaling conversion as shown below,

  $\begin{array}{c}\text{5 centimeters model's wingspan}=2\text{ meters actual wingspan}\\ \text{so 1 centimeter model's wingspan}=\frac{2}{5}\text{ meters actual wingspan}\\ \text{so 28}\text{.5 centimeters model's wingspan}=\frac{2}{5}\times \text{28}\text{.5 meters actual wingspan}\\ \text{=}\frac{57}{5}\text{ meters actual wingspan}\\ \text{=}11.4\text{ meters actual wingspan}\end{array}$

Thus, the actual wingspan is 11.4 meters.