0.25 Phy1220: relationships among kinematics, newton's laws, vectors

Table of contents

• Preface
  • General
  • Prerequisites
  • Supplemental material
• Discussion
  • An ideal rocket example
    • Leg A
    • Leg B
    • Leg C
    • Leg D
• Do the calculations
• 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 illustrates relationships among kinematics, Newton's laws, vectors, 2D linear motion, 2D forces, momentum, work, energy, and power in aformat 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 modules include:

• 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.

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

A wrap-up module

The next module following this one will involve circular motion, which will be a major change in direction (no pun intended). Therefore, in this module, Iwill work through a major example involving a rocket that will tie together much of what you have learned in earlier modules.

Before we get to that example, however, let's do a quick review on external and internal forces.

A quick review of external forces

You learned in an earlier module that when work is done on an object by external forces, the total mechanical energy possessed by the object, consisting of kinetic energy plus potential energy,must change.

The work done on the object by external forces can be positive, in which case the total mechanical energy will increase. The work can be negative, in which case the total mechanical energy will decrease. The change in mechanical energy will be equal to the net work that is done on the object.