0.27 Phy1240: circular motion -- speed and velocity

Table of contents

• Preface
  • General
  • Prerequisites
  • Supplemental material
• Discussion
  • Uniform circular motion
  • Average speed
  • Velocity
• A thought experiment
• 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 speed and velocity for circular motion 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 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

Much of what you learned in earlier modules pertaining to linear motion applies also to circular motion.

Uniform circular motion

A ride on a carousel

Suppose that you and three of your friends go to an amusement park and take a ride on the carousel. In case, you are unfamiliar with a carousel, it is usuallya large disk containing models of horses positioned around concentric circles. Children sit on the horses while the disk spins. As the disk spins, music plays,and the horses go up and down.

Pay for a ride

Usually, you pay for a ride and when the carousel stops, you get on one the horses. After everyone is safely on a horse, the disk starts to spin. Aftergetting up to speed, the disk spins at the same speed for a few minutes. Then it slows down and stops. Everyone gets off, and a new group of riders get on.

Ignore the up and down motion

For this discussion, we will ignore the music and the up and down motion of the horses and consider only the circular motion.