Georgia Institute of Technology

**Dynamics – AE 2220-A****School of Aerospace Engineering**Georgia Institute of Technology

**TR 9:30-10:45 a.m., Skiles 249**

**Prof. Dewey H. Hodges**

**Office: 200-C SSTC/Weber**

**Phone: 4-8201**

**E-mail: dhodges@gatech.edu**

**Time and place**: The class hours are 9:30-10:45 a.m., Tuesdays and Fridays, and the place is Skiles 249.

**Office Hours**: My office hours are Mondays, 8:30-10:00 a.m. and Fridays, 9:30-11 a.m. The TA is Mr. Siddarth Niranjan Babu <siddarth@gatech.edu> whose office is in Weber 201. His office hours are Wednesdays and Thursdays, 3:00-4:30 p.m. You may phone or e-mail either of us for appointments if these hours are not suitable. Help sessions (maximum of one per week) will be held on a weekday evening, in a Guggenheim classroom if one is available.

**Text**: The text is the outstanding book by McGill and King, *An Introduction to Dynamics, Fourth Edition*. The notation and methodology of the text will be followed strictly, and you are expected to do the same. You are also expected to read the assignments listed in the syllabus and to come to class with questions on this material. Any material in the reading assignments will be considered as fair game for the quizzes and final exam, even if this material is not covered in the lectures. The text carefully distinguishes between vectors and scalars, and rightfully so. If you do not do so as well, you will get hopelessly confused and fail the course. I will accelerate that process by docking points from the quiz grades of anyone who fails to make the appropriate distinctions, and the amount deducted will increase with each test. If you passed Statics, but you still cannot carry out basic vector operations such as dot and cross products, you will most definitely fail this course (as well you should!) unless you get your act together. Human lives may depend on your correctly carrying out a cross product!

**Lectures**: The lectures cover theoretical foundations of dynamics. The syllabus will be followed as closely as possible. Because of time constraints I will have to cover some material very quickly. You are expected to wisely use time outside of class and be prepared to spend three hours outside class for every hour you spend in class in order to learn this material. This strongly suggests that you be willing to ask questions in class for clarification. If you do not ask questions, I will be forced to conclude that you understand the material, and understand it well. If I am convinced that the class as a whole has attempted to solve an assigned problem, I will happily answer questions about it in class. If I am convinced that you as an individual have attempted to solve an assigned problem, I will happily answer questions about it outside class.

**Homework**: About nine problems per week are assigned (on average). If you can work the homework problems on your own, it is very likely that you will also be able to work problems on the quizzes and on the final exam. If you choose the dishonest route of copying solutions from fraternity files, solution manuals, etc., you’re violating the honor code. Consequently, you will not learn how to work the problems on your own, and you will likely fail the course (as well you should!). See this article: http://www.sciencenews.org/view/generic/id/57656/title/Homework_makes_the_grade! You can watch someone else solve dynamics problems until doomsday and never learn anything. You will learn best by thinking them through on your own. Working on homework in groups of more than two is not permitted. However, working in pairs is acceptable as long as you really interact and both of you really contribute. If you play the role of a “sponge” you will learn next to nothing. You should attempt to solve the assigned problems and as many related problems for which you have time. If you have difficulty doing the problems, please raise a question in class. Alternatively, you may see the TA or me during our scheduled office hours. If you do come, please have specific questions. Do not simply ask, “How do you work problem 2.32?” I will want to know whether or not you have really tried to solve it and what you have tried. Work your nine problems per week, and you should be able to do the quizzes and final without last-minute panic. Problems will be collected according to the schedule in the **detailed syllabus**. Late homework is not accepted. On the attached syllabus, each quiz has in parentheses by it the article numbers covered on the quiz. Make certain that you have solved the assigned problems associated with those articles before the last class prior to each quiz so you can ask questions in class about the problems. The assigned homework sets will be weighted as 50 out of 675 points toward your grade (see “Grading” below). If, at the end of the semester, you are on the borderline between two grades, your homework grade will be increased to the full 50 points if you turn in a complete and correct set of homework at the final exam. No partial credit will be given: It must be **complete**, and it must be **correct**.

**Quizzes/exams**: there will be at least seven quizzes, of about 30 minutes duration each, and a comprehensive final examination. You will be permitted to overwrite one quiz grade with the grade from a computer project. The quizzes will count 50 points each (total=350), the homework a total of 50 points, and the final will count 275 points for a total of 675 points. Should you miss class on a quiz day, a makeup quiz will only be given if you have a doctor’s note stating that you are too sick to attend class or if you have a death in your immediate family. In the latter case, if possible, you must notify me before the quiz. You must either send me e-mail or you must phone our office, leaving a voice-mail message if I am not in. Note: in homework, on quizzes or on the final you may be asked to “show that” certain results are obtained. If it is determined that you are trying to deceive me into thinking that you have correctly obtained the result when in fact you really have not, you will get zero credit for that problem. If this happens more than once, you will receive a zero on all tests on which you are caught after the first time. On the attached syllabus, each quiz has in parentheses by it the article numbers covered on the quiz. Make certain that you have solved the assigned problems associated with those articles before the last class prior to each quiz so you can ask questions in class about the problems.

Projects must be turned in no later than the last day of class. A grade of C on the project means a substandard project that fails to meet the stated requirements in some substantial way; a B would mean a good project that meets most of the stated requirements; and an A would mean a project that meets all the stated requirements perfectly. A grade of 50/50 would mean that your project substantially exceeds the stated requirements. You may validate your code by comparing results with those of others, but you must do all your work independently. If there is evidence of unauthorized collusion, this will be treated as a potential **honor code** violation and reported to the Dean of Students.

**Grading**: Grading will be based on your percentage grade out of 675 points. 60-70% is a D, 70-80% a C, 80-90% a B, and 90% or better an A. Do not expect the course to be easy or the grades to be “curved” as others may do. I do not make use of the class average in determining your grade. This course provides a foundation to upper division courses, and I would not be doing you a favor to pass you if you do not know the material.

**Course Objectives for Students:**

- To be able to derive equations for the kinematics and kinetics of particles in three-dimensional motion
- To be able to derive and use equations for the kinematics of rigid bodies in two-dimensional motion
- To be able to set up and solve equations of motion for rigid bodies in two-dimensional motion
- To be able to apply work-energy principles in the solution of rigid-body dynamics problems in two dimensions
- To be able to derive and use equations for kinematics of rigid bodies in three-dimensional motion
- To be able to set up equations of motion for rigid bodies in three-dimensional motion