Chapter 8.1, Problem 22PSB

a

To determine

To find:The actual length of the real plane.

Answer to Problem 22PSB

The length of real plane is 756 in

Explanation of Solution

Given information:

The length of model plane is $10\frac{1}{2}\text{in}$

The scale of the model is 1:72

Formula used:

Use the scale

Multiply the model length by assumed scale

Calculation:

Since,

Scale given is

1 in = 72 in$\therefore$ The length of real plane

  $\begin{array}{l}=72\times 10.5\text{ in}\\ \text{=756 in}\end{array}$

b

To determine

To find:The length of wing span in the model if the length of the real wing span is 43.5 ft.

Answer to Problem 22PSB

The length of wing span in the model is 7.25 in

Explanation of Solution

Given information

The real plane has wingspan of 43. 5 ft

Formula used

Divide the real length of wingspan by 72 in

Convert ft into inches using

1 ft = 12 in

Calculation

Since

1 ft = 12 in

The real length of wingspan

  $=43.5\times 12\text{ in}$

  $\therefore$ The length of model wingspan

= $\begin{array}{l}=\frac{43.5\times 12}{72}\\ =7.25\text{ in}\end{array}$

c

To determine

To find:The length of the model plane.

Answer to Problem 22PSB

The length of model plane is 7.0 in

Explanation of Solution

Given information

Scale 1:48

When scale was 1:72, length of model plane was 10.5 in

Formula used:

Multiply the length of model length by $\frac{48}{72}$

Calculation:

The length of model plane, when scale is 1:48, will be

  $\begin{array}{l}10.5\times \frac{48}{72}\text{ in}\\ =10.5\times \frac{2}{3}\text{ in}\\ =3.5\times 2\text{ in}\\ =7\text{ in}\end{array}$