Students have published the first Physics in Action podcast episode of season 3, featuring a look at physics in the Star Wars universe, a retro-styled look at Newton’s Laws of Motion, and an investigation into springs. You can subscribe for free through iTunes, or download directly from the APlusPhysics.com website. Great start to a new season, guys!
Although by no means an exhaustive list, these 10 quick tips may help you secure that extra point or two on your upcoming Regents Physics exam.
Most importantly, use your reference table. When in doubt, write down the information you’re asked to find, what you’re given, and use your reference table to help you narrow down what you should be doing. In the free response part of the test, make sure to show your work in detail with a formula, substitution with units, and an answer with units.
Find these and many more tips for success at APlusPhysics.com.
Mid-Term results have been compiled and published. In general, scores are right in line with performance within the last few years. The exam itself was styled after the Regents Exam which is given at the end of the school year, and included topics from all aspects of Newtonian Mechanics (roughly half of the Regents Exam). This included 46 multiple choice questions, and 25 open-ended, or “free response,” type questions. Students were given 180 minutes to complete the exam, as well as a formula sheet (Regents Physics Reference Table), and a ruler. Students were permitted the use of a scientific calculator.
Summary Data
Summary data from this year’s exam, along with the previous two years of data, are shown at right. 
Average score on the exam, with a fairly generous curve, was 76%, compared to 73% in 2010 and 74% in 2009. Median score was 78%, two points higher than last year’s exam, and right in line with 2009 scores. Percentage of students scoring above 85%, considered “Mastery Level” by Regents Physics standards, was 25%, slightly lower than in 2010 and 2009, but passing percentage was 83%, several points higher than in past years. Even more promising is a glance at a histogram 
breaking down student scores further. This data indicates that we have many students in the 80-85% range. Past history has shown me that it is quite possible for students to improve their scores from 10-15% points between now and the actual Regents Exam in June with focused effort, study, and motivation. This indicates the potential for outstanding standardized exam performance in June if students buckle down and focus their efforts. Unfortunately, the Physics Regents Exam is usually one of the last tests offered (sometimes even after official graduation), so obtaining and maintaining student focus at this point of the year can be a challenge.
Cluster Data
Breaking down exam performance by topic, we observe students demonstrating a very strong understanding of Newton’s Laws of Motion, Hooke’s Law (springs), and Work and Energy. These have been focus areas during the year, although there is room for further improvement in understanding Newton’s 2nd Law as well as momentum and impulse.
Cluster data indicates weaknesses in Newton’s Law of Universal Gravitation, although a deeper look at the questions and errors themselves indicates that most of the confusion here is a result of mathematical errors rather than conceptual misunderstandings. This is being re-emphasized as we work through Coulomb’s Law / Electrical Force problems, which utilize almost the exact same mathematical model. Other areas for improvement include 2-D Kinematics (projectile motion), a perennial challenge, and utilizing and understanding the metric system, a topic that has been emphasized and will continue to be reviewed throughout the year. Performance on momentum problems was, unsurprisingly, problematic. This relates directly to a “class as a whole” issue with independent practice and motivation throughout that unit, and will be our top priority for review in mid-June.
Conclusions
Student performance is in line with, if not slightly above, expectations for this point in the year. With a focused effort, students can fairly routinely increase their scores 10 to 15 percentage points by June. For struggling students, a variety of remediation protocols are being put in place, including the entire course content and sample quizzes available on the web, tailored directly to this course’s requirements (APlusPhysics.com), video lectures on topics corresponding directly to our textbook (Hippocampus), and even review sessions which can be viewed from any computer supporting iTunes (Windows, Mac, Linux, etc.) as well as iPods, iPhones, Blackberries, Android devices, etc. All of these resources are available both in the classroom as well as the school library for those who don’t have ready access to these resources outside of school.
Data has also been broken down to the same level for individual students, and will be utilized to develop both entire-class and individual review plans to allow students to focus on areas that will provide the biggest “bang for the buck” in their studies.
An interesting application of work combined with the Force and Displacement graph is examining the force applied by a spring. The more you stretch a spring, the greater the force of the spring… similarly, the more you compress a spring, the greater the force. This can be modeled as a linear relationship, where the force applied by the spring is equal to some constant time the displacement of the spring. Written mathematically:
F is the force of the spring in newtons, x is the displacement of the spring from its equilibrium (or rest) position, in meters, and k is the spring constant which tells you how stiff or powerful a spring is, in Newtons per meter. The larger the spring constant, k, the more force the spring applies per amount of displacement.
You can determine the spring constant of a spring by making a graph of the force from a spring on the y-axis, and placing the displacement of the spring from its equilibrium, or rest position, on the x-axis. The slope of the graph will give you the spring constant. For the case of the spring depicted in the graph at right, we can find the spring constant as follows:
You must have done work to compress or stretch the spring, since you applied a force and caused a displacement. How can you find the work done in stretching or compressing the spring? By taking the area under the graph. For the spring shown, to displace the spring 0.1m, we can find the work done as shown:
