0.26 Phy1230: vector subtraction

Table of contents

• Preface
  • General
  • Prerequisites
  • Viewing tip
    • Figures
    • Listings
  • Supplemental material
• Discussion
• Examples of vector subtraction
  • The parallelogram method
  • Angles, approaches, and vector naming convention
  • Trigonometric solutions
  • Orthogonal vectors
    • Graphical solution for Cs=B+A
    • Graphical solution for Dd=B-A
    • Trigonometric solution for Cs=B+A and Dd=B-A
  • Same magnitude, 45-degree angle
    • Graphical solutions for sum and difference vectors
  • Sum and difference for smaller and smaller angles
• Run the script
• Resources
• Miscellaneous

Preface

General

This module is part of a book (or collection) designed to make physics concepts accessible to blind students. The collection is intended to supplement but not to replace thetextbook in an introductory course in high school or college physics.

This module explains vector subtraction in a format that is accessible to blind students.

Prerequisites

In addition to an Internet connection and a browser, you will need the following tools (as a minimum) to work through the exercises in these modules:

• A graph board for plotting graphs and vector diagrams ( (External Link) ).
• A protractor for measuring angles ( (External Link) ).
• An audio screen reader that is compatible with your operating system, such as the NonVisual Desktop Access program (NVDA), which is freelyavailable at (External Link) .
• A refreshable Braille display capable of providing a line by line tactile output of information displayed on the computer monitor ( (External Link) ).
• A device to create Braille labels. Will be used to label graphs constructed on the graph board.

The minimum prerequisites for understanding the material in these modulesinclude:

• A good understanding of algebra.
• An understanding of the use of a graph board for plotting graphs and vector diagrams ( (External Link) ).
• An understanding of the use of a protractor for measuring angles ( (External Link) ).
• A basic understanding of the use of sine, cosine, and tangent from trigonometry ( (External Link) ).
• An introductory understanding of JavaScript programming ( (External Link) and (External Link) ).
• An understanding of all of the material covered in the earlier modules in this collection.

Viewing tip

I recommend that you open another copy of this document in a separate browser window and use the following links to easily find and view the figuresand listings while you are reading about them.

Figures

• Figure 1 . Program output for orthogonal vectors.
• Figure 2 . Program output for smaller and smaller angles.

Listings

• Listing 1 . Add and subtract vectors using trigonometry.

Supplemental material

I recommend that you also study the other lessons in my extensive collection of online programming tutorials. You will find a consolidated index at www.DickBaldwin.com .

Discussion

Earlier lessons have dealt quite a lot with vector addition, but I have had very little to say about vector subtraction. That is because we haven't had muchneed for vector subtraction until now. The next module will deal with circular motion and the need for understanding vector subtraction will be paramount inunderstanding the material in that lesson.