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Well, yes, you're here because you have to be (it's part of the physics course, and you have to take physics...), but there's a more fundamental reason. The laboratory is the workshop of the elementary physics course. Physical science is not a body of theory, or dogma, regardless of how orderly we make it seem in lectures or textbooks. Instead it is a structure -- elegantly streamlined in some of its parts, ramshackle in others -- built of observed relationships between experimental phenomena. It is really unthinkable (or it ought to be) to go through an introductory physics course without some hands-on experience of making physical measurements. This is especially true because the physics one treats as an introductory course consists of models of physical reality which are highly simplified; the real world is always messier than that! In lab, you get a chance to try out the physical principles you study in class, and dig into some of their quirks and limitations; and also to get acquainted with techniques of observation, measurement, evaluation, and analysis that are valuable skills in their own right. A sense of how well one can isolate a simple principle from the real-world complications (friction, dirty electrical contacts, background ionization, and so on and on) in which it's embedded is something that you can get only from actual experience in the laboratory.
So, mainly, you're here to have the experience of making elementary physical measurements. Some of the secondary objectives are: to become familiar with some common instruments and methods; to learn some techniques for evaluating your data and analyzing the uncertainties in it; and to learn how to organize, record, and present the results of laboratory work. What I'll try to do in this chapter is to give you an overview of some of the things you will be doing, and learning to do, in working toward these objectives.
The first two chapters of this manual contain some general instructions for laboratory work, meant to help you get as much as possible out of the time you spend in introductory physics labs. The instructions in these preliminary chapters apply to any of the introductory laboratories. (For that matter, most of them will apply to whatever further lab work you do in your technical courses.) Of course, you'll have more than one instructor in the different courses, and chances are that each will have his own preferences about how you proceed in detail: when labs are due, how partnerships are graded, how experiments are scheduled, particular ways of laying out data tables or tricks of error analysis, modified experiment procedures, and so on. He or she will make you aware of these in the first (organizational) meeting of your lab section.
How should you use these notes? Maybe the best way is just to make yourself acquainted, right away, with what's in them, and then keep them available as a reference and resource through the rest of your lab work. It won't take more than bout an hour to read through the introductory chapters, just with enough attention to find out what's there and mark the bits that aren't immediately clear. You should do this before the first working session of your lab. As the quarter goes on, you can look for ways to apply, in particular experiments, the things you find in them. Your instructor, too, will refer you to points in the notes that will help you correct or improve things that you're doing. Most of what's in this chapter -- how you proceed in the lab, how you lay out a lab notebook and what ought to appear in it -- will be applicable to most of the experiments you do. The same is true of chapter 2, which deals with the analysis of experimental errors.
The instructions for the specific experiments that are done in each course begin in Chapter 3. Each chapter contains the experiments for one course. It's very important that you study each experiment before you come into the laboratory, so that you come in knowing what you're going to do, and why, and more or less how. (To encourage this, some instructors make a practice of giving a short "pre-quiz" at the start of each lab meeting.) Insofar as possible, the experiments will deal with concepts you've already studied in class, but scheduling constraints sometimes make this impossible. References to specific sections of your text and other standard physics texts are given with each experiment; read them.
The apparatus you need for each experiment is listed in the instructions. You'll usually find it set out for you when you come in. The equipment provided is adequate for the purposes of each laboratory exercise. (On the other hand, evaluating the limitations of your equipment is an important part of evaluating the experiment you've done.) It ranges from state-of-the-art to homemade-25-years-ago. You won't encounter many very fragile items in these labs, but all the equipment is delicate enough to call for reasonable care in dealing with it. Your instructor will sometimes have special instructions, or warnings, or modifications of the equipment to tell you about. Give him a chance to do so before you plunge ahead -- don't start working with the apparatus until he says to get going. In particular, never connect any electrical equipment to a power source until your instructor has checked and approved the circuit.
When you are done with your equipment, leave it in at least as good order as you found it. If there've been any malfunctions or unexplained behavior, if you've busted anything, make sure your instructor knows about it before you leave. Someone else has to use this gear tomorrow!
As you carry out an experiment, be aware of what's happening to you! Make rough checks of your results as your data is being taken, so you can spot it if you have a sick meter or just a misconception of what you're trying to do. You'll probably want a calculator with you in the lab (it should include trig functions and logarithms); but also you should train yourself to make crude calculations -- one or two significant figures -- in your head, as a way of checking what you're doing as you go. This is something anyone can do with a little practice.
Remember too that an essential part of any physical measurement is an assessment of its uncertainty. You must learn to be aware, as you work, of the limitations of each measurement that you make, and record whatever information you'll need to estimate the experimental error in your results. This is a lot of what Chapter 2 is about.
Finally: as is true of so many things, you'll find that physics labs become much less painful as you get on top of what you're doing and become aware of what, and how, you are learning from the experience. As unlikely as it might seem: enjoy yourself!