A model known as stopping sight distance is used by civil engineers to design roadways. This simple model estimates the distance a driver needs in order to stop his car while traveling at a certain speed after detecting a hazard. The model proposed by the American Association of State Highway Officials (AASHO) is given by v2 + TV, 2g(f + G) where we have the following. S = stopping sight distance (ft) V = initial speed (ft/s) g = acceleration due to gravity, 32.2 ft/s2 f = coefficient of friction between tires and roadways

Elements Of Electromagnetics
7th Edition
ISBN:9780190698614
Author:Sadiku, Matthew N. O.
Publisher:Sadiku, Matthew N. O.
ChapterMA: Math Assessment
Section: Chapter Questions
Problem 1.1MA
icon
Related questions
Question

I need help with this question. :)

A model known as **stopping sight distance** is used by civil engineers to design roadways. This simple model estimates the distance a driver needs in order to stop his car while traveling at a certain speed after detecting a hazard. The model proposed by the American Association of State Highway Officials (AASHO) is given by:

\[ S = \frac{V^2}{2g(f \pm G)} + TV, \]

where we have the following:

- \( S = \) stopping sight distance (ft)
- \( V = \) initial speed (ft/s)
- \( g = \) acceleration due to gravity, 32.2 ft/s\(^2\)
- \( f = \) coefficient of friction between tires and roadways
- \( G = \) grade of road
- \( T = \) driver reaction time (s)

---

**Problem:**

What are the appropriate units for \( f \) and \( G \) if the preceding equation is to be homogeneous in units? Show all steps of your work.

- Starting with the equation \( S = \frac{V^2}{2g(f \pm G)} + TV \), the units of \( S \) are ft, the units of \( V^2 \) are \(\_\_\_\_\), the units of \( g \) are ft/s\(^2\), and the units of the product \( TV \) are \(\_\_\_\_\). Rearranging the equation above to solve for \( f \pm G \), we obtain the following. (Use any variable or symbol stated above as necessary. Do not substitute numerical values; use variables only.)

\[ f \pm G = \]

- Then, the units of \( f \pm G \) are:

\[\frac{\text{ft}^2/\text{s}^2}{\_\_\_\_\} = \_\_\_\_\ .\]
Transcribed Image Text:A model known as **stopping sight distance** is used by civil engineers to design roadways. This simple model estimates the distance a driver needs in order to stop his car while traveling at a certain speed after detecting a hazard. The model proposed by the American Association of State Highway Officials (AASHO) is given by: \[ S = \frac{V^2}{2g(f \pm G)} + TV, \] where we have the following: - \( S = \) stopping sight distance (ft) - \( V = \) initial speed (ft/s) - \( g = \) acceleration due to gravity, 32.2 ft/s\(^2\) - \( f = \) coefficient of friction between tires and roadways - \( G = \) grade of road - \( T = \) driver reaction time (s) --- **Problem:** What are the appropriate units for \( f \) and \( G \) if the preceding equation is to be homogeneous in units? Show all steps of your work. - Starting with the equation \( S = \frac{V^2}{2g(f \pm G)} + TV \), the units of \( S \) are ft, the units of \( V^2 \) are \(\_\_\_\_\), the units of \( g \) are ft/s\(^2\), and the units of the product \( TV \) are \(\_\_\_\_\). Rearranging the equation above to solve for \( f \pm G \), we obtain the following. (Use any variable or symbol stated above as necessary. Do not substitute numerical values; use variables only.) \[ f \pm G = \] - Then, the units of \( f \pm G \) are: \[\frac{\text{ft}^2/\text{s}^2}{\_\_\_\_\} = \_\_\_\_\ .\]
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 5 steps

Blurred answer
Knowledge Booster
Elastic Constants and Their Relationship
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, mechanical-engineering and related others by exploring similar questions and additional content below.
Recommended textbooks for you
Elements Of Electromagnetics
Elements Of Electromagnetics
Mechanical Engineering
ISBN:
9780190698614
Author:
Sadiku, Matthew N. O.
Publisher:
Oxford University Press
Mechanics of Materials (10th Edition)
Mechanics of Materials (10th Edition)
Mechanical Engineering
ISBN:
9780134319650
Author:
Russell C. Hibbeler
Publisher:
PEARSON
Thermodynamics: An Engineering Approach
Thermodynamics: An Engineering Approach
Mechanical Engineering
ISBN:
9781259822674
Author:
Yunus A. Cengel Dr., Michael A. Boles
Publisher:
McGraw-Hill Education
Control Systems Engineering
Control Systems Engineering
Mechanical Engineering
ISBN:
9781118170519
Author:
Norman S. Nise
Publisher:
WILEY
Mechanics of Materials (MindTap Course List)
Mechanics of Materials (MindTap Course List)
Mechanical Engineering
ISBN:
9781337093347
Author:
Barry J. Goodno, James M. Gere
Publisher:
Cengage Learning
Engineering Mechanics: Statics
Engineering Mechanics: Statics
Mechanical Engineering
ISBN:
9781118807330
Author:
James L. Meriam, L. G. Kraige, J. N. Bolton
Publisher:
WILEY