Power and machines 101
February 11th, 2009 by Stephen R. Schaffter | Physics 101 | | Comments Off
Power is defined as how fast work is done. We find this by dividing the work done by the time needed to do it. The units of power are watts (1 W = 1 J/s) or horsepower.
In automobiles, horsepower is usually associated with speed. This is a vague term, however, since there are many different ways to measure the horsepower of a car’s engine.
A machine is something that can change the direction or size of a force. Since a machine obeys conservation of energy, the amount of work put out by a machine can never be greater than the amount put in.
The work-energy theorem 101
February 11th, 2009 by Stephen R. Schaffter | Physics 101 | | Comments Off
Whenever mechanical energy such as kinetic and potential energy are added to a system, work has been done on the system. When a system does work, energy is removed from the system.
This is a restatement of the principle of conservation of energy.
In order for a force to do work on a system, the force must cause a displacement in the direction of the force. If the force and displacement are at right angles, no work is done.
A satellite orbiting at a fixed distance will not speed up, slow down, or change height. Gravity does no work on it.
Work and kinetic energy 101
February 9th, 2009 by Stephen R. Schaffter | Physics 101 | | Comments Off
Work is defined as an applied force that causes something to move through a distance. If there is no movement, there is no work. If there is movement but no moving force, no work.
The unit of force is the Joule, which is 1 N·m.
Energy can be defined as the ability to do work, or as the ability to apply a force.
Kinetic energy is associated with movement. More mass means more kinetic energy. The speed term is squared, and has a greater effect than the mass term. Doubling the speed means the energy goes up by a factor of four.
Physics 101 - A different view
January 24th, 2009 by Stephen R. Schaffter | General, Physics 101, education | | Comments Off
I came across a novel idea for writing: the 101 word short story.
I thought this might be a good idea to try for my classes: a post each day composed of 101 words that summarizes the topic of that day.
This approach would force me to discuss only the most important aspects of a given subject. Will you get a comprehensive education by reading these excerpts? Probably not. But you will be able to see what we talk about each day, and, over time a fairly complete picture of physics will emerge.
Think of it as a one-minute radio spot each day.
Odd things to know about oneself…
November 2nd, 2008 by Stephen R. Schaffter | General | | 0 Comments
Get your own pirate name from piratequiz.com.
part of the fidius.org network
This quiz was provided by - Wholesale Clothing
Created by The Car Connection
What teaching is all about…
September 20th, 2008 by Stephen R. Schaffter | Opinion, Personal | | 2 Comments
When Bankei held his seclusion-weeks of meditation, pupils from many parts of Japan came to attend. During one of these gatherings a pupil was caught stealing. The matter was reported to Bankei with the request that the culprit be expelled. Bankei ignored the case.
Later the pupil was caught in a similar act, and again Bankei disregarded the matter. This angered the other pupils, who drew up a petition asking for the dismissal of the thief, stating that otherwise they would leave in a body.
When Bankei had read the petition he called everyone before him. “You are wise brothers,” he told them. “You know what is right and what is not right. You may go somewhere else to study if you wish, but this poor brother does not even know right from wrong. Who will teach him if I do not? I am going to keep him here even if all the rest of you leave.”
A torrent of tears cleansed the face of the brother who had stolen. All desire to steal had vanished.
Source:
Anon. 2008. The 10 Very Best Zen Stories | Awakeblogger - Personal Development and Spirituality Blog. awakeblogger.com. September 20. http://www.awakeblogger.com/2008/09/the-10-very-best-zen-stories/.
Songs I Like, Part I
September 7th, 2008 by Stephen R. Schaffter | General, Opinion, Personal | | 0 Comments
Dolores O’Riordan has an amazing voice. Of course, so does Amy Lee.
The Turboencubulator
July 6th, 2008 by Stephen R. Schaffter | Engineering, Humor | | 0 Comments
Regardless of the new technology, sometimes the old “mechanical” approach to things are the best:
Romans had nerds, too!
June 17th, 2008 by Stephen R. Schaffter | Games, Personal | | 0 Comments
I ran across this on the website of Christies, the international auction house. Here is an example of a “Roman glass gaming die”:
It sold for $17,925, and according to Christies, “Modern scholarship has not yet established the game for which these dice were used.”
It’s a D20, used for games like Carcere et Chimaerae!
Valediction, 2008
June 16th, 2008 by Stephen R. Schaffter | General, Personal | | 0 Comments
This is the speech I give as a farewell to each of my classes.
This is the last time that we will ever meet together as a class. Nine months ago, we were strangers to one another. Today, we are a class. In the time that we have been together, I hope that I have made your lives richer and fuller, as you surely have done for my life.
For one, brief moment, we are still a class.
For one last time, I am your teacher. This is, for most of you, the last time that I speak to you from a position of authority.
All of us wonder from time to time whether our lives have meaning, and whether or not we make a difference. All of us would like to think that we matter, and that what we do affects others in a lasting way.
Over the years, I have realized that all of us can make a difference, and all of our lives can have meaning, if we give our time and our efforts to others.
The way that I see myself is as a little man that stands at the edge of a pond. Every once in awhile, I throw a pebble into that pond, and watch as the little waves ripple across the surface. Sometimes they combine with other little waves to form great waves, and sometimes they form areas of peace and calm. Together, these waves make a pattern as infinitely complex and beautiful as will be found anywhere in this vast cosmos.
My words to you, my students, are my little pebbles, and together, we make something more powerful and wonderful than any one of us can ever imagine.
As I become older, I find that it is important to me that I pass on what little collection of advice that I have. Whether this advice is any good, I don’t know, but I am going to give it to you anyhow, since you are still my students.
This is the best profession for me that I can imagine. I have said that many, many times. Each day brings me new joy and new insights into my life. I am a truly happy man, and I want for you the happiness, the contentment, and the genuine feeling of accomplishment that I feel every day.
Life is not always easy or pleasant. All of us are discouraged, disappointed, disheartened, or disillusioned at some times in our lives. All of us have hard times, and we are sad, scared, and alone at many times in our lives. This is normal, and natural, and you should neither worry about it nor fear it. These hard times will end through your actions, your hopes, and your confidence in your ability to make a good, good life.
Live your lives well. Do not demand that the world reward you with riches or recognition for what you do. Do the best that you can every day, in whatever you do. Respect and love yourself for who you are and what you do for others. With this, all other things, including fame and material wealth, become unimportant.
Believe in yourselves, and believe those who see your greatness. Be quick to see and acknowledge greatness in others as well. Mark Twain once said, “Keep away from those who try to belittle your ambitions. Small people always do that, but the really great make you believe that you too can become great.”
He also said, “Twenty years from now you will be more disappointed by the things that you didn’t do than by the ones you did do… Explore. Dream. Discover.” I cannot think of better advice, especially for young, talented people like you.
Remember your families, and remember from where you came. You are the culmination of all of the blood, sweat, tears, and love of your parents and all the generations of your ancestors. All of them are alive in you at this moment. Each is present in your body. You are the continuation of all of these people. Celebrate and cherish this heritage. Honor those who came before you by making your life the best it can be.
You will find that there are two families that you have in this life: the one that you are born with, and the one that you make. The first is a matter of accident; the other is by choice. Make a good family. Fill it with people who love you for who you are, and love them for who they are. Spend time with your loved ones, and make time if none exists.
Remember your friends. Remember that true friendship isn’t about being there when it’s convenient; it’s about being there when it’s not. Know who your friends are, and let them know how much they mean to you by words and deeds as often as possible. They will appreciate this more than you will ever know.
Through distance and time, you will lose track of many of your friends. This is a part of all of our lives, and something that happens all too often. Rather than being saddened by this, rejoice in the impact that your friends have had on you, and what you have done to change their lives. Celebrate your friendships now, for it will be too late when you move on to another part of your life.
And remember, in all things, that your happiness must be shared.
Thousands of candles can be lighted from a single candle, and the life of the candle will not be shortened nor its brightness diminished. Happiness never decreases by being shared.
Good bye, my dear, dear students.
Good bye, good luck, and have a good, good life.
Mr. Schaffter - Do Not Write on This Exam
