Chapter 8.2, Problem 31E

(a)

To determine

To find: The distance you travel.

Answer to Problem 31E

The required distance is $64\text{ft}$ .

Explanation of Solution

Given information: You travel on feet from Room $103$ to Room $117$ .

  

Calculation: Using the segment Addition Postulate to get the distance,

  $\begin{array}{l}\text{R}\text{.}\text{103}\text{to R}\text{.121}=\text{R}\text{.103 to R}\text{.117}+\text{R}\text{.119 to R}\text{.121}\\ 86-22=\text{R}\text{.103 to R}\text{.117}+22-22\left[\because \text{subtract 22}\right]\\ \text{R}\text{.103 to R}\text{.117}=\text{86}-\text{22}\\ \text{R}\text{.103 to R}\text{.117}=64\text{ft}\end{array}$

(b)

To determine

To find: The time taken by you to reach Room $117$

Answer to Problem 31E

The required time is $0.24\text{min}$ .

Explanation of Solution

Given information: Your speed is $4.4\text{feet per second}$ .

  

Formula used: $\text{time}=\frac{\text{distance}}{\text{speed}}$

Calculation: Using the segment Addition Postulate to get the distance,

  $\begin{array}{l}\text{R}\text{.}\text{103}\text{to R}\text{.121}=\text{R}\text{.103 to R}\text{.117}+\text{R}\text{.119 to R}\text{.121}\\ 86-22=\text{R}\text{.103 to R}\text{.117}+22-22\left[\because \text{subtract 22}\right]\\ \text{R}\text{.103 to R}\text{.117}=\text{86}-\text{22}\\ \text{R}\text{.103 to R}\text{.117}=64\text{ft}\end{array}$

The required time taken to reach Room $117$ :

  $\begin{array}{l}\text{time}=\frac{\text{distance}}{\text{speed}}\\ =\frac{64\text{ft}}{4.4\text{ft/s}}\times \frac{1}{60}\\ =0.24\text{min}\end{array}$

(c)

To determine

To explain: The taken time is more in part (b)

Answer to Problem 31E

Maybe some obstacles are there in the corridor that makes us stop or slow, that’s why we will take more time.

Explanation of Solution

Given information: Your speed is $4.4\text{feet per second}$ .

  

It might be possible that we take more time to reach than that given in part (b) because there are some obstacles, maybe people are present in the corridor, which makes you either stop or slow down.