### Physics 1600 at Auburn

I was teaching Physics 1600 (also known as PHYS1600, or Engineering Physics) as a TA for Dr. Marllin Simon in 2007 - 2013. Its short description is presented at the Auburn Introductory Physics Courses page. The course is essentially introductory mechanics presenting the following topics throughout the semester: one-dimensional kinematics, two-dimensional kinematics, dynamics and Newton's laws, dynamics of circular motion, conservation laws (energy and momentum), rotational kinematics, rotational dynamics, harmonic motion.

#### Questions and misconceptions

Every semester students come to class holding similar misconceptions about the course, or expecting it to be very different. Here I will try to summarize and explain those misconceptions.

**Math preparation.**The course description says that Physics 1600 "gives a thorough treatment of classical physics__using calculus__". In fact, many students who enroll in this course have*algebra*as their main struggle. Solving physics problems requires algebra; as soon as you have figured out what to do with your physical model, you have to actually*do*it to get the answer. If you have a difficulty dividing*a*^{2}-*b*^{2}by*a-b*or expanding sin(*x+y*), you will have a big difficulty advancing in this course. Algebra skills are a habit and can be learned by exercise; take your time doing as many algebra and trigonometry exercises as possible, and when you enter the course, math will not stand in the way of your understanding physics.**Problem solving.**Problem solving is your main physics activity. Although the course includes both lab and recitation (problem-solving) classes, you need to be able to solve physics problems to pass the three tests during the semester and the final. Normally, students perform well at labs but badly at recitations, and the latter is of critical importance for your success in this course. You are recommended to do at least five problems every day on the topic you are currently studying. You can use your physics textbook or other numerous sources. I would highly recommend Irodov's "Problems in General Physics", which is an excellent problem book used for freshman and sophomore scientists and engineers in Russia. (You will probably need a viewer for DJVU e-books. If you are on Windows, go here and download and install the latest version; if you are on MacOS, go here and do the same; if you are on Linux, you probably have it and in any case you already know what to do.)**Analytical vs. numerical calculation.**Sometimes students complain that there are too many "variables" in the examples we do on the blackboard and they would rather have more "numbers". This idea may come from two misconceptions about the course.First, this is a

*calculus-based*engineering physics course that requires extensive use of*algebra*. If you enroll in this course, you are assumed to have good skills in*arithmetic*as well as in algebra; therefore, we do not make you exercise much in arithmetic. In calculus, you operate*functions*to find integrals and derivatives; the derivative of any*number*is zero. Besides, if numerical calculation is needed, you can always use calculators or computer software. To perform these operations, you do not need a physics course.Second, the solution to a physics problem is the

*formula*which includes the*given data*, as well as universal constants (if any), in an algebraic form. This formula contains all necessary information we need to know about the particular physical setup. You can always do the numerical calculation by substituting certain numeric values of the given data, but this is secondary. Therefore, when doing physics problems, you should always derive the answer analytically (that is, in "variables"), and then, if required, do the numerical calculation. At recitations, we normally will not spend time on the latter.Many students are tempted to plug in the numeric values in the beginning of the solution because they believe it makes things easier. Actually, it may mess up the solution completely due to the following reasons.

**You lose all information about the relationships of the parameters of the system.**The purpose of solving a problem is to find the relationship of the unknown parameter to the known ones. For example, consider an answerwherea = g (m _{1}-m_{2})/(m_{1}+m_{2})*m*are the masses in a certain setup and_{1}, m_{2}*a*is their acceleration (*g*is the free fall acceleration). From here you can make a series of conclusions: acceleration depends on*g*(that means on the Moon it will be different); when the masses are equal, the acceleration becomes zero; the direction of acceleration depends on which mass is bigger (*a*changes the sign depending on which one is greater). If you plugged in the numbers in the beginning and derived the answer, say, 2.44 m/s^{2}, you would not be able to know any of the above, as well as get any further information from the answer 2.44 m/s^{2}.**You lose the ability to do a dimensions check**(unless you explicitly wrote them next to each number). In the example above, in fact, you would not even be sure if you got 2.44 m/s^{2}and not 2.44 kg or 2.44 m (which are clearly not accelerations and are therefore wrong answers)! Dimensions are what makes physics calculations very different from plain algebra: you cannot add or subtract different dimensions (like add 5 meters to 3 seconds, or subtract 20 kilograms from 110 volts). Your analytical answer to the problem is easy to check: make sure all additions and subtractions are of the same dimensions, and the answer is actually in the dimensions you expect. In the example above, we clearly see that we subtract two masses in the numerator (same dimensions) and add two masses in the denominator (same dimensions); mass is then multiplied by acceleration and divided by mass, which gives us acceleration (as we expected). The dimensions check is the first thing you should do with your answer: if it contains impossible additions or subtractions (like*m + g*or*m - m*^{2}or*m*+1 where*m*is mass), or if the answer came out in different dimensions (for example, you were looking for accerelation and your answer is in kilograms), then the answer is clearly wrong. Evidently, if you plug in the numbers in the beginning, you cannot do any of this.**Your solution is not any good for the same system with even slightly different parameter values.**The number you get after doing the whole thing numerically is for the particular numerical parameters of the system only. If you have to answer a second question or work another problem where the same setup has one or two parameters with different numbers, you will have to re-do the whole solution. With the analytical answer, you just plug in different numbers in your formula (or enter different numbers in your spreadsheet).**You don't know if your answer is exact or an approximation.**Let's say you had to find a certain point on the rod whose length is 10 cm. You did it numerically from the start and got 3.33333 cm on your calculator. It looks like it is one third of the length of the rod, but now you can't be sure. Maybe it is not*exactly*1/3? Maybe it will be a different one for a different rod? Maybe it will be 3.33333 cm for*any*rod, and thus you have (re-)discovered some universal constant? You don't know.**Your solution is difficult to check for errors by another person.**When we grade your papers, we can follow you easily when you have an analytical solution. If your answer is incorrect but you started on correct premises, we can find where you made an error which was carried on. Therefore, you can get partial credit depending on what part of the solution is correct. Sometimes you do everything correctly and just mess up the circled answer -- then you are sure to get most credit. However, it does not seem possible to track down the numeric part this easily: we have to "restore" the meanings of your numeric values, for example, if you have 9.8 somewhere, it is likely to be*g*; it is more difficult to recognize*g*/2 in the number 4.9; besides it may be something else as well. Therefore, the reviewer of your paper in this case will only look at your final answer -- and if the number is not correct, then your solution is assumed to be wrong. Further analysis of your answer, including the dimensions check, cannot be done either.

**Memorizing formulas.**A formula is a concise form of a statement.is another way of saying "a force of gravitational attraction between two masses equals their product times the gravitational constant divided by the squared distance between them". The mathematical form is much shorter and more convenient to work with. However, you must always understand what each variable stands for. Oftentimes students memorize the formulas used during the course without understanding what they mean. It is the same as if you memorized a sentence in a language that you do not know: although you know the sequence of letters or sounds, you have no idea what this sentence says. Such memorization is useless; it will not help you solve problems for your homework or exam. As an example, take the centripetal (normal) acceleration formulaF = Gm _{1}m_{2}/r^{2}: you must understand what isa _{n}= v^{2}/r*v*and what is*r*here. Some students say that*r*stands for "radius", but you must know the radius of*what*is meant here: in many mechanical setups, there is more than one thing that may have a radius.In short, memorize ideas, not formulas.

#### Feedback

To have a better idea of the students' feedback, I used the ratemyprofessors.com page pertaining to Dr. Simon's courses. Although the majority of the comments are likely to be an emotional response and therefore provide little to no useful feedback, I singled out the ideas that were more or less common. Some of the comments are from Dr. Simon's Physics 1500 students, who study the same topics but without calculus. Spelling and grammar errors have been left intact.

this class sucks! hardest class i've ever taken in my college carrer. do not take if u can help it. i just took the final like 30 min ago. i studed atleast 10 hours a day for the last 4 days. there were 8 parts to the test. i didn't get but one problem completely right. studying for his tests is usless. he just makes them so hard no one can get it

This student also rated the class quality as "poor", based on its difficulty level. Using such reasoning, a better-quality class should be easier to take. Apparently, to make a best-quality engineer, you almost don't have to study anything.

Jokes aside, this complaint is rather common. Therefore, I should warn many students that the class might not seem easy. By taking this class, you let us know that you want to become an engineer or scientist. This requires hard work. Those who didn't take physics in high school will have to study much. Those who aren't at ease with math (algebra, geometry, and trigonometry) will have to spend some time learning to use it efficiently.

Worst class i've ever taken. Studied harder than I ever have in my life for the first test and made a 21. The rest of my test were about the same.

Again, it may very well be that you are not yet prepared for Physics 1600. If you still want to be an engineer or scientist, work more on what caused you the most difficulty and take the class again. Or change your major: why do something that you don't like? Is it really worth struggling?

I'm an A student, I won a full scholarship to Auburn, and I struggled a little in his class. BUT I sucked it up, put the hours in and got an A. You CAN PASS with a 50 average in his class. If you at least attempt all the homework, all the labs, and study, you should be able to pass.

Actually, you are supposed to do (not just attempt) all the homework, labs, and quizzes to succeed in the course. You are given the opportunity to learn a lot for your profession, don't miss it.

I made a B grade however this teacher barely teaches and gets so caught up in his teaching that you practically have to teach yourself.

You always have to teach yourself. You do your homework, read the textbook, solve problems on your own. The teacher can tell you the useful concepts and work examples, but he cannot make you start learning if you don't. If you don't succeed, the last thing you should put the blame on is your teacher. It's not very wise: there are likely to be stronger factors for your lack of success.

He rushes through concepts just so he can get them done. he doesn't care if you learn or if what he's saying makes sense. He expects you to know way too much going in to the class. He makes the class way harder than it should be and does a poor job teaching it. You will learn absolutely nothing.

Actually, this class is easy -- one of the easiest in the Physics Department. Try taking relativistic quantum mechanics (PHYS8100) to see the difference. There is no way it should be easier; otherwise, how will you learn your engineering physics? How will you proceed in the engineering program with harder subjects? The problem is, people come with all sorts of the background in physics and math, and there is a certain background bandwidth within which taking this class is reasonable. Beyond this bandwidth, this class will seem either impossibly hard or ridiculously easy. Ask yourself again if you are ready to take it or whether you need more time to refresh your physics and math skills.

Class is a castiron ****. Go in knowing you will spend alot of time on it. Do ALL the homework, do most of the extra credit, and get the little pre and post tests done on time and you will survive. Made a 74, 59, 30. Studied alot for the final and it whipped my ass, but still got a B. Simon is a good guy who wants to help. Content is just hard.

Bonus points for understanding. Any university student is *assumed* to be willing to fulfill the course requirements if he takes it.

Horrible teaching method. He doesn't give you a formula sheet, so you memorize them, right? Nope. He doesn't want you to do that. He wants you to derive the formula, using other variables that would find you the variables for the actual formula. Make sense? I didn't think so.

See "Analytical vs. numerical calculation" and "Memorizing formulas" above.

Amount of homework is RIDICULOUS and its all online.

There are ten problems assigned per week. Above, based on my experience, I suggested doing five similar problems *every day*. Am I expecting too much?

Phyics is going to be hard, so get over that.

I wish I could be this concise here...

Let me finish with some informative and thought-out comments Dr. Simon's students left about his courses.

Dr. Simon is an excellent teacher and he makes you understand Physics rather than just memorize equations. Do not focus on studying homework problems. Really understand his problems worked in class (CAPSTONE problems) and know how to do EVERY single problem put on the board

if you are after a degree, do not take Simon. However, if you want an education, he is perfect!

I really like him. He does do a lot of stuff in class that doesn't seem very useful, but if you take good notes and really listen and try to understand the material instead of memorize it, his class is not too difficult. He is helpful as well (if you can find him) and explains the stuff very well, although sometimes too detailed.

This is one of the hardest classes I've ever had. That being said, Dr. Simon is an awesome professor! He makes it impossible to fail if you do your homework and lab reports. He wants you to learn and curves at the end. Very fair and really cares about his students. I would recomend him to anyone!

Going to class scared me because he never made any sense in class, but go to class so you can get clicker points. Go to recitation and lab and don't forget to do the homework- get the solutions manual. I failed the first tests but then made B's and A's because things started to make sense. He scales at the end, and I made an A. Don't be scared.

Engineering Physics is a going to be tough, don't doubt that. My test grades were 34, 30, 30, 62. I did near perfect on the homework/labs/recitation. I went to class every day for clicker points. And completed all the extra credit. My final grade was a C.

Physics is a tough class no matter who you take. Dr. Simon's tests are very hard. Do ALL of the homework, go to class to get clicker points, and do all the extra credit. He does a pretty big scale at the end of the semester. If you just want to pass, I recommend taking him.

#### Exercises

Here are the math exercises that you are encouraged to try.

- Algebra, geometry, and trigonometry
- Calculus: integrals and derivatives. Page 1, page 2.

#### Course help

These are help files for each topic studied in Physics 1600 in a nutshell with example problems and solutions.