Physics 104 - How Things Work - Spring, 1999

Individual Term Paper

Your term paper should be 1500 to 1750 words long (approximately 5 double-spaced, typewritten pages). It must be typed, using a reasonable font, point size, and margins. Your paper should focus on one object from the world around you and identify within that object several different physical concepts that make the object what it is. You should describe what these physical concepts are and how they contribute to the behavior of the object. Well chosen objects will involve physical concepts that range from mechanics to electricity to heat to optics. However, avoid an object that is so broad that you can only describe a tiny piece of it.

You should be able to cover the main structure of the object in enough detail to make the reader feel like you actually understand "how it works" overall. The grade you receive will reflect how well your paper conveys an overall understanding of how the object works, including a fair amount of specificity. Don't be vague or mushy. In the physical world, there really are correct and incorrect statements. Vague statements that can be misinterpreted in a way that makes them incorrect are not helpful. Please check your grammar and spelling, and proofread your papers. Bad writing will reduce your grade.

For example, imagine that you were writing a paper on a windsurfer. You should note that its behavior involves buoyancy (it floats), drag (it has a top speed), friction (your feet stay on it), inclined planes (the keel and sail), and various forces (the wind, your arms, the water on the keel). You should describe how these various concepts create the specific behavior you see in the windsurfer (e.g. how buoyancy keeps the board from sinking and what changes in the buoyancy, up or down, might do to the behavior of the boat.) You should describe how the forces of the wind and the water work together to accelerate the windsurfer in a particular direction. You might describe why you can't go directly into the wind, no matter how hard you try.

You are encouraged to use references, written or otherwise, but create the paper on your own. You may not work with anyone else on an individual term paper. You may, however, get technical information from a knowledgeable person (e.g. a repairperson or an engineer) as long as you do the thinking about that information and you write the paper. Visit the library. Attach a simple sheet listing all of your references to the back of your paper.

Try to keep the paper well structured and fairly specific. Please don't ramble. If the reader gets lost, the reader will not be impressed. Types of subjects to avoid:

- "A radio wave" (too specific - no range of concepts)

- "A city" (too broad - every possible principle)

- "A vehicle" (too vague)

- "Pumps" (too focused on a principle rather than an object -- try a water pump instead)

Do not assume that the grader reading your paper will understand specialized jargon or that he or she already knows exactly how the object you are writing about works. You must pursue each physical issue carefully and in sufficient detail that a person knowledgeable in basic physics will understand how that issue relates to the workings of the object. You must also ensure that the reader has a good overall picture of the object. In short, structure the paper carefully so that it provides a good overall picture and many specific details that fit clearly into that overall picture. Your paper should be readable and informative to a student who is doing well in this class.

Physics 104 is a physics course and your term paper will be judged according to how effective it is at explaining the physics and physical concepts that make the object work. In particular, the A range papers will be those that get right to work discussing physical concepts in their object and work efficiently to cover many of the important ways in which physics contributes to the workings of their object. B range papers will be those that discuss some physical concepts, but either bog down while discussing only a few physical concepts, have significant mistakes in them, or waste too much space on non-physics issues such as history, users' manuals, description, or engineering instructions. C range papers will be those that fail almost completely to discuss physical concepts and instead dwell on history, users' manuals, description, or engineering instructions. If your paper doesn't contain much that you learned in this course (or its equivalent), you probably haven't written a physics paper.

Here examples of what to do or not to do in writing a paper about paper clips:

HOW PAPER CLIPS WORK
(Physical Concepts - The Desired Approach)

Paper clips are small objects, usually constructed from metal wire, that serve to hold several sheets of paper together as a single unit. In effect, a paper clip consists of two metal surfaces that are pressed against one another by the elasticity of the metal wire from which the paper clip is built. As you distort the paper clip away from its equilibrium shape, by spreading the two surfaces apart, it experiences restoring forces. These forces tend to return the paper clip to its equilibrium shape and push the two surfaces together. Because the paper clip behaves like a spring, the restoring forces are proportional to the distance separating the two surfaces. When several sheets of paper are placed between the two surfaces, the restoring forces on the metal surfaces cause them to exert inward, compressing forces on the paper sheets. Because each sheet of paper does not accelerate, it is clear that the sheet experiences no net force. Instead, forces appear between each sheet of paper and its neighbors to oppose the compressing forces from the paper clip. The force between each sheet and its neighbor gives rise to friction between the sheets. The sheets cannot slide easily across one another because they will experience frictional forces whenever there is relative motion.......

(This paragraph is very extreme and I do not expect even the best papers to be this serious and intense. The point is that you should get down to business: tell the reader what you are going to discuss, why it is important, and then discuss it. Focus primarily on physical issues, although you may include other aspects of the object to make the paper more interesting and readable.)

HOW PAPER CLIPS WORK
(A Historical Study - Wrong Approach #1)

Paper clips are used to hold several sheets of paper together. Paper clips were invented in 1872 by John Smith. Prior to the invention of the paper clip, people had resorted to pinning sheets of paper together with straight pins. Pins damaged the sheets and offered the possibility of injury. Because it avoided these two shortcomings, the paper clip was an immediate success. For his invention, Smith received U.S. patent #12345. This was among the first patents ever granted. In the patent, Smith described the paper clip as a device for restraining several leafs of paper together as a single document.

The first paper clips suffered from several short comings. It was difficult to insert the pages between the metal sections. In the decade following the initial patent, dozens of different designs appear. Many of these designs still exist today. The most common paper clip style is the Gem.....

(While this may be fun to write and read, it gives the reader very little idea of how the object works. You could write this paper without knowing any physics)

HOW PAPER CLIPS WORK
(A User's Manual - Wrong Approach #2)

Paper clips are used to hold several sheets of paper together. The stack of papers is collected together by holding it upright on a table and tapping it lightly on the table's surface. If many sheets are to be clipped together, a device called a jogger is sometimes used to align the sheets together neatly. The paper is then slipped between the two halves of the paper clip until the stack is fully inserted. As long as you avoid inserting so much paper that the clip is deformed, it will hold the sheets together. If you have too much paper for a small clip, you should find a larger clip......

(Again, you could write this paper without knowing any physics. This is not a "how the paper clip works" paper, it is a "how to use a paper clip" paper.

HOW PAPER CLIPS WORK
(Description - Wrong Approach #3)

Paper clips are used to hold several sheets of paper together. They are constructed from wire that has been bent in several places. There are usually three 180° bends so that the overall piece of metal forms a spiral. The spiral is somewhat disguised because it includes a number of straight sections. The metal wire is normally shiny, silver in color, and about 0.05 inches in diameter. It is also quite stiff. Common paper clips range in size from less than half an inch long to over three inches. Sometimes paper clips are used a desk ornaments/organizers, in which case they may be as much as 6 inches long.

In use, the two halves of the paper clip are spread apart and the stack of paper is gripped between the two halves. Bigger paper clips generally grip the paper more tightly than smaller paper clips. There are also special paper clips for holding together large stacks of paper. The most common clip of this type is called the Ideal clip. It consists of two overlapping triangles. A much thicker wire is used to form the ideal paper clip.....

(Another paper that you could write without knowing any physics. This is not a "how the paper clip works" paper, it is a "what the paper clip is like" paper. Even though the paper tries to explain a bit about how the paper clip works, the explanation is vague and without any physical concepts in it. You can write a very long, detailed description of how something "works," without including any physical concepts in it. For example: "the stick pushes on the knob, which turns 35° and lowers the shelf, causing the rod to stretch until it breaks through the surface". No physics.)

HOW PAPER CLIPS WORK
(Engineering Instructions - Wrong Approach #4)

Paper clips are used to hold several sheets of paper together. A paper clip is made by bending a steel wire in three places. This bending is done in a special jig so that each segment of the clip has precisely the right length. If the bending is done incorrectly, the wire segments will not be closely parallel to one another and the paper clip will be less effective at holding together the paper. To construct the most common type of paper clip, the Gem clip, the wire is bent in a smooth arc, over an angle of 180°, at each of three locations. In other clips, one or more of the smooth arcs are replaced by pairs of angular 90° bends. These bends make it easier to insert sheets into the clip, but are more likely to damage the paper during insertion.

Because the wire comes from the factory on spools, it has a natural curvature and must be straightened before use. This straightening is performed by passing the wire through a group of pulleys. Once it is straight, an automatic device measures the proper length for the paper clip.....

(Still another paper that you could write without knowing any physics. This is not a "how the paper clip works" paper, it is a "how to make a paper clip" paper.)

HOW PAPER CLIPS WORK
(Over packaged, Physics Avoidance Maneuver - Wrong Approach #5)

As a humanities major, I rarely have an opportunity to look into the concepts and mechanisms that create the structure of the universe around us. So much of what we see in this glorious world of ours can be explained if only we take the time to investigate it. Through the use of logic, as developed over the centuries since at least the time of the Greeks, blah blah blah....(somewhere on page 2, the reader is told that this paper is about the paper clip, but it is not until page 3 that our attention turns specifically to the paper clip itself. Two paragraphs later, the paper returns to contemplating the cosmos and the place of physics and science in that cosmos)

(This paper avoids the issue of trying to explain how the paper clip works by packaging a little meat in a large amount of filler. Some wonderful, A+ papers that students have submitted in past semesters have included interesting and clever packaging. However, the packaging in those papers served as a condiment for the meat inside, not as a way to avoid the physical issues.)