Getting a 5 on the AP® Physics C Mechanics exam is one of the most rewarding accomplishments that a high school student can achieve. It shows that you a more than prepared for an upper-level university physics course, and sets you apart from your competitors when applying to colleges. However, getting a 5 is not easy. About one third of the students taking the AP® Physics C Mechanics exam will get a 5. Make sure you are part of that exemplary class of students by following these instructions on how to study for the AP® Physics C Mechanics exam.

You will need:

• Notes from class (if you took the class in high school)

• Prep book – The most recommended prep books by high school students are Barron’s and Princeton Review. Both books tend to contain practice problems and exams that are significantly harder than the actual exam.
• Flash cards – You can learn how to make your own effective flash cards here.
• Practice Exams – You will find practice exams in your prep book, but try to find six to eight old AP® exams online as well. You can find the exams of the past several years at AP® Central, the official AP® exam website hosted by Collegeboard. Past AP® exams will give you the best idea of how will do on the exam, as the questions are very similar.

Before beginning to study for the exam, you should be clear on the topics that will be covered on the exam, and whether or not the exam will focus on certain topics more than
others. A list of the topics on the AP® Physics C Mechanics exam can be found below.

Topics Covered on the AP® Physics C Mechanics exam

• Kinematics – 18%
• Newton’s Laws of Motion – 20%
• Work, Energy, Power – 14%
• Systems of Particles, Linear Momentum – 12%
• Circular Motion and Rotation – 18%
• Oscillations and Gravitation – 18%

As you can see, the exam covers all of the topics taught in a high school AP® Physics C Mechanics course, and covers them all fairly equally. However, what this topic distribution does not tell you is that this is the topic distribution for the entire exam. You may find that within the two section of the exam, the multiple choice and free response sections, one section is almost void in one topic and the other is predominantly based on that topic. For example, while taking the multiple choice section, you may notice very few questions on Newton’s laws of motion. Given this, you should expect that the free response section will compensate for this by containing one or more questions that require you to use Newton’s laws of motion.

As you begin studying, it is important to note the differences between the multiple choice and the free response questions of the AP® Physics C Mechanics exam, as these differences will affect the way you should approach studying for each type of questions. The multiple choice questions on the exam tend to focus more on your knowledge of the course material as a whole. You will be tested on your ability to recall relevant formulas and use them correctly. To put it simply, you will be tested on your breadth of knowledge of the basic principles of physics. On the other hand, the free response questions on the exam tend to focus more on your ability to apply relevant physics concepts and formulas to an extended problem. Formulas and concepts from different topics may be needed complete a problem, and you will almost always have to perform some form of mathematical calculation to solve a problem. Where the multiple choice section tests you on your breadth of knowledge of physics, the free response section tests you on your depth of knowledge of the principles of physics, and how they relate to each other. If this is not clear, do not worry. We will go over practice problems from each section later on in this article. Below is a more in depth comparison of the multiple choice and free response questions.

Multiple Choice Questions

• Tests breadth of information
• Simple questions – apply a formula
• Pros – if you know the applicable formula, you should get the question right
• Cons – there is no partial credit given.
• Tips – Always write down the relevant formulas before starting the section.

Free Response Questions

• Tests depth of information
• Extended questions – apply multiple formulas from different topics and your own derivations
• Pros – There is partial credit given.
• Cons – You will need to correctly use and derive formulas.
• Tips – Understand the types of questions you may come across

As you begin studying, you should start by reviewing all of the material that will be covered on the exam. Using your AP® Physics C review book and your notes from class, read over the main ideas of each topic, and note down important formulas. Doing a complete review will put you in a mindset to begin working on physics. At this point, it is also a good idea to print out the formula sheet that you will be given for the exam so that you can familiarize yourself with the information you will have to complete the exam.

The Multiple Choice Section

The key to doing well on the multiple choice section of the AP® Physics C Mechanics exam is practice. This section is a test of your basic knowledge of all of the topics on the exam. It is also a test of your ability to answer a multitude of questions on several different topics within a short period of time. You will be given 45 minutes to complete 35 questions, so you will need to be able to answer every question quickly and accurately. In your prep book, you will find practice questions for the exam. You will find even more questions on AP® exams from previous years. Take as many of these as you can until you can complete two to three exams quickly and correctly within 45 minutes. Although you will have a formula sheet for this section of the exam, it’s best if you don’t need to reference it. Given this, you should use flashcards with the formulas on the back and a relevant AP® problem on the front to study the formulas you will need to remember for the exam. More information on how to create AP® Physics flashcards can be found here.

Now we will go over a practice multiple choice problem from the AP® Physics C Course Description.

If a particle moves in a plane so that its position is described by the functions x = Acos(wt) and y = Asin(wt), the particle is
a) moving with constant speed along a circle
b) moving with varying speed along a circle
c) moving with constant acceleration along a straight line
d) moving along a parabola
e) oscillating back and forth along a straight line

This question requires you to do little more than recall the position formulas for circular motion. Upon recalling those, it should become obvious that the formulas given in the question are those same formulas. From there, it is easy to see that the answer is A.

The Free Response Section

The free response section the AP® Physics C Mechanics exam requires a different approach. Similarly to the multiple choice section of the exam, the key to doing well on the free response section of the exam is practice. However, to complete the free response section correctly, you also must know how to apply your knowledge and complete calculations that you have not necessarily seen in class or in your textbook. In short, you should be able to adapt your bank of information to a given situation. Flashcards can also come in handy in the free response section of the exam,as there are vocabulary words that you must understand within the context of the exam to answer the question properly. You will be given 45 minutes to complete three free response questions, and you will receive a formula sheet. To study for the free response section, take as many practice tests as possible under testing conditions (45 minutes per section with no outside resources, and use the flashcards to fully answer the questions with as much work shown as possible. This is the only section where you will receive partial credit, so give yourself the best chance to get the most points on each question by showing all of your calculations.

Now we will go over a practice AP® Physics C Mechanics free response problem from the 2014 AP® Physics C Mechanics exam.

A large circular disk of mass m and radius R is initially stationary on a horizontal icy surface. A person of mass m/2 stands on the edge of the disk. Without slipping on the disk, the person throws a large stone of mass m/20 horizontally at initial speed v from a height h above the ice in a radial direction. The coefficient of friction between the disk and the ice is n. All velocities are measured relative to the ground. The time it takes to throw the stone is negligible. Express all algebraic answers in terms of m, R, v, h, n, and fundamental constants, as appropriate.

a) Derive an expression for the length of time it will take the stone to strike the ice.
b) Assuming that the disk is free to slide on the ice, derive an expression for the speed
of the disk and the person immediately after the stone is thrown.

The first part of this question requires you to recall and rewrite the formula for vertical motion from kinematics. From there you must simply, substitute in the variable h for height and gravity for acceleration and then solve for time to arrive at the correct answer. The second part of the question requires you to use the equation for conservation of momentum, substitute in the momentum of the person/disk and the stone, and solve for the velocity of the person/disk.This free response problem shows the applications of two different topics on one problem, and how to connect them in order to find a solution.

As long as you follow these study guidelines and examples, you are guaranteed to do well on the AP® Physics C Mechanics exam.

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