(The What)
Definition of an Introductory Physics Course: A mixture of learning about physics (a coherent overview of the major concepts and ideas of physics) and learning to do physics (learning methods of reasoning, observation, measurement and analysis of data).
Expectations: This is neither a math course nor a memorization course.
I. Classical Mechanics - Motion and Change, a macroscopic view. Everything you will study in physics is about change and motion.
1. Study of motion
Two kinds of motion: Constant = motionless or straight line motion with constant speed.
Changing motion = changing speed or direction
Force: That which changes motion
Compare the motion of a pasco cart with that of a HoverCraft
2. Momentum = p = mv = quantification of motion
Force = change in mv over time = Æ(mv)/Æt = m(Æv/Æt) or (Æm/Æt)v or m(Æv/Æt)+ (Æm/Æt)v
Demo motion with change of mass using the airplane. We'll look at this later
But is change in motion just change in speed?
Look at a ball on a string being twirled in a circle with constant speed.
So v must indicate both speed and direction (we call it velocity), and any change in either speed or direction of motion constitutes a change in velocity which implies a force acting on a mass, or, a nonzero Æv/Æt = acceleration (denoted by the letter a)
3. The law of momentum: Look at elastic collisions and discuss what is constant (conserved).
Look also at someone spinning on the stool and discuss what is conserved.
4. Look at different causes of force: Contact forces - Push or pull
Action-at-a-distance forces - gravity, electricity, magnetism.
Look at demo of all three, and discuss briefly a fourth "passive" force that just lies in wait for you, friction.
(This quarter we'll only look at gravity as an action-at-a-distance force.)
5. Look at objects rolling down a hill and discuss Potential and Kinetic Energy. Do demo of long and short hill of same height.
6. Notice the different final speeds of two different objects w/same diameter and mass rolling down a hill and discuss rotational Kinetic Energy.
7. Lead into discussion of Temperature and Heat which we'll do at the end of this semester, which leads into electricity, which we'll do next semester. Pass around the three different objects & ask which is hottest, and do demo with crank thing.
(The How)
The concepts of physics we will study are the inventions of a few people, (Galileo, Newton, Joule, Faraday, and Einstein) between 1600 to 1900. They are not necessarily intuitively obvious.
The techniques we will use to understand these concepts and how to use them to solve problems were developed by a few people, (Priscilla Laws, Ron Thornton, David Sokoloff, David Maloney, Alan Van Huevelen, and Paul Hewitt, perhaps even a couple by yours truely) between 1986 and the present.
We also have a new idea, the "Warm-up Quiz", and idea of Evelyn Patterson and Gregor Novak. Your responses to these will be used to design the next class discussion!
One cannot learn to shoot a basket, play tennis, snow ski, or physics by listening to lectures.
Physics is easy to learn but difficult to be taught. The keyword here is active participation.
Physics comes with a considerable vocabulary. To learn it one must use it almost daily. Some of these words have common usuages that are different from the physics meaning. A few have the same meaning, but many people have misconceptions about what they actually mean or imply.
When confronted with evidence that their ideas about these fundamental concepts are wrong, some people have a tendency to lose faith in their judgement about any physical phenomenon. They may learn to correct the few misconceptions they had, but they throw out a whole bunch of stuff they believed that was actually right! The key word here is few. Most of your intuition is correct!
The best way to learn about ones misconceptions is through prediction-observation-explanation experiments . The best way to gain initial understanding of many of the key vocabulary words is to do experiments involving them.
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The primary objective of studying physics is to solve problems and explain phenomena.
There is no way to memorize every conceivable situation and how to solve it. To try to do this is to totally miss the point. The real power of school of phyiscs lies in the fact that it enables us to take almost any observable phenomenon and reduce it to one of only three basic principles.
1. Newton's laws of motion.
2. The fact that momentum is conserved in any isolated system.
3. The fact that energy is also conserved in all situations and must be accounted for.
In class: We will discuss techniques used to solve problems, student responses to the warm-ups, have concepts drills and have problems presented by the students.
Solving problems:
1. Every problem starts with a frame of reference.
2. Next one must determine events of interest.
3. Decide which of the three principles you plan to use.
4. If (1) Draw motion diagrams, (MD 's) displacement, velocity and acceleration vs time curves, Draw Free Body Diagrams (FBD's), use this information to write equations, then solve the equations.
If (2) make sure the system is isolated. Make sure all velocities are relative to the same refreence frame.
Solve equation Po = Pf.
If (3) Draw energy bar charts for clarity. Set Eo = Ef and solve .
Labs
Physicists do a lot of forethought and preparation before doing labs. Labs are conducted to test hypotheses to see if they are correct. Discoveries only come from failures. You will be real physicists. You should strive to know the outcome of labs before you arrive. Most of your write up except for filling in data, analysis of data, and conclusion should be complete when you arrive at the lab.
At large universities labs are often out of sync with lectures because of logistics.
Here we will usually present new concepts first in labs because that is the best way to uncover misconceptions and overcome them. Research is devastatingly clear about this. You will always be your own best teacher in physics. Simply telling people facts then letting them do labs to verify the facts is only about ten percent as effective in teaching the concepts as letting them try it and see for themselves .
(The Why)
It is a statistical fact that people with a fair understanding of physics (a combination of reasoning skills and understanding of the basic concepts of physics) are better stewards of society and the planet. They are less likely to be addicted to drugs or gambling, and they take better care of the planet.
The world is a shocking mess- magazines and the news are full of environmental disasters.
The causes are known, to a few- in a word, technology
The solutions are also known, to a few- in a word, technology. (You might want to read a Union of Concerned Scientists mag)
The problem is ignorance-Too few understand the causes and too few understand the mathematical dynamics of the situation.
Examples:
The current shortage of fish in the ocean"crisis". 30 years ago a team of scientists-financed with your tax dollars- predicted that rapid advances in technology would enable total depletion of the oceans by the turn of the century, and drew up a harvest plan which , if followed by all people globally , would enable us to harvest up to ten times as many fish annually as were then being harvested without reducing the fish populations at all. Those in the fishing industry refused to listen to science 30 years ago so now your tax dollars must take care of them like helpless children and we have a desolated ocean, which may not be repairable.
The soon to come shortage of timber for those in the logging industry. We'll be expected to retrain them and support them in the manner to which they've become accustomed while doing so and we'll have lost forests literally thousands of years in the making. (Already over 98% of the old growth forests have been leveled.)
Energy production and current usage thereof is terribly destructive to the ecosystem of the planet. Solutions are already available. We just need to decide whether we want to make the planet healthy or a handful of oil barons even richer.
If you think fish crises and timber shortages are bad, wait until the water crisis hits. It will occur during your lifetime if we don't collectively change our behavior patterns.
The plastics problem. HCFC's are produced both in manufacture and disposal. (Try to go thru a single day without using something made of plastic only once, and then throwing it away.)
Enough people start their engines before fastening their seat belts each day in this country alone and waste enough energy to power a city with a half a million people in it. (Atlanta, for instance)
The situation requires a global democratic solution. (i.o.w. every man, woman, and child must understand the problem and its urgency, and agree to engage in the solution).
People must understand the problem because it is impossible to pass enough laws and hire enough police to force people to behave appropriately. The problems themselves are dynamic, and people are going to have to understand the problems enough to constantly judge their own behavior against the problems at the moment and to act in ways that will eventually dissolve the problems.
But I don't want you to think of physics as solely some kind of gloom and doom prevention machine.
Physics is a study of the basic ingredients of our existence and how they interact with each other. This study itself is by no means concluded. Not only can an understanding of the basic concepts of physics make you a more effective engineer or scientists, but it can also make life easier and more fun, and there's always the chance of you making a big discovery.
Examples:
Michael Faraday made some of the greatest contributions in electricity and magnetism even though he never clearly understood why he was so great because he was mathematically illiterate and never understood the magnitude of his own discoveries.
A 14 year old kid unravelled the mystery of sudden death of whole villages in Africa which led to measures to prevent these disasters in the future.
Another 14 year old designed a simple apparatus to measure the force on a superconductor by a magnet ( he figured it out when he was 12), solving a problem that had baffled scientists for three decades. He was discovered when he presented his apparatus at a science fair.
So my objectives for you are:
1. To obtain a basic overview of the physics of our existence as it is known at this time.
2. To obtain some training in the methods whereby all this information was obtained so that you can analyze new situations as they unfold and also so that you too may make new discoveries.
3. To enlist you in the army of those engaged in expanding this understanding and utilizing this information to enhance and perpetuate our existence rather than terminating it.
i.o.w. I want you to obtain enough information and skill to become an intelligent player of the game of life as we know it.
1. Join the CACC Science Team. Adopt third grade class for year. We'll divide into groups of two to four students, pick physics concepts, break them down into simple fun activities for kids, then go out to the same third grade class four or five times a semester (approximately every two weeks) and do the activities with the kids. It helps the third graders develop an early interest in science, and teaching physics is the best way to learn it.
2. Design a Physics T-shirt. Something you'd actually like to wear that would help charge up people's interest in physics and the sciences. Get guaranteed sales before we go to print with them. (Make a deal with some teachers to give bonus points to buy one, that's the sleazy we sell them.)
3. Organize a trip. Seeing physics in action is always a real inspiration for learning. We always take a trip in the spring to the Pensacola Naval station to tour their pilot training facility. I'm considering a fall trip to Argonne National Laboratory near Chicago. That place is incredible. The only down side is the day's drive up and back. Also, we'd have to either raise money or pay for 2 nights lodging and buy meals. Or perhaps make it a Christmas vacation trip and fly up to Marquette Michigan and ski for a couple of days??
4. Think of a money raising event and make it happen.
5. The lighting experiment.
6. Join a solar car contest.
7. Come up with your own project.
Other Possible Projects
100 mpg carb
fire ants
equilibrium lab
solar power system