Appendices - 5 Steps to a 5: AP Physics C (2016)

5 Steps to a 5: AP Physics C (2016)



Physics C Equations

Four-Minute Drill Prompts

Web Sites





Read Chapter 6 about memorizing equations for more help with learning not only what the equations say, but also what they mean.

You”ll notice that the C equation sheet often expresses relationships in calculus terms. Don”t let that confuse you; for example, though impulse is expressed as an integral of force with respect to time, you should also interpret that as force times time if the force is constant, or as the area under a force vs. time graph.

Remember, your textbook might use slightly different symbols.




The lists that follow are designed to help you study equations. Each prompt refers to a specific equation on the AP Equations sheet (we”ve listed the prompts in the same order in which the equations appear on the Equations sheet). So, for example, the prompt “Net force” refers to the equation, “F net = ma .”

There are several ways to use these prompts. First, you can use them as a self-test: For each prompt, write down the corresponding equation on a separate sheet of paper. Then check the equations you wrote down against the AP Equations sheet to see if you got any wrong. You can also use these prompts when you study with a friend: Have your friend read the prompts to you, and you respond by reciting the appropriate equation. Try to go through the list as fast as possible without making a mistake. Last, your physics teacher can use these prompts to lead your class through a four-minute drill, which is an activity we describe in Chapter 6 .


1st kinematics equation

2nd kinematics equation

3rd kinematics equation

Net force

Force in terms of momentum


Definition of momentum

Force of friction


Kinetic energy


Power—alternate expression

Gravitational potential energy near a planet

Centripetal acceleration


Newton”s second law for rotation

Definition of rotational inertia

Position of the center of mass

Conversion between linear and angular velocity

Angular momentum

Rotational kinetic energy

1st rotational kinematics equation

2nd rotational kinematics equation

Force of a spring (The negative sign reminds you that the spring force is a restoring force, always acting toward the equilibrium point.)

Potential energy of a spring

Period in terms of angular frequency and standard frequency

Period of a mass on a spring

Period of a pendulum

Gravitational force between two massive objects

Gravitational potential energy between two massive objects (Don”t use unless an object is far away from a planet”s surface.)

Electricity and Magnetism

Electric force between two point charges

Definition of electric field

Gauss”s law (Though you should never actually take an integral when using this.)

How to find electric field in terms of potential

Potential energy in terms of potential, and then potential energy between two point charges (This line on the equation sheet really has two different equations. PE = qV is always valid, but PE = kqq/r is only valid between two point charges.)

The electric potential at some point due to surrounding point charges

Definition of capacitance

Capacitance of a parallel-plate capacitor with a dielectric substance of constant κ added

How to add parallel capacitors

How to add series capacitors

Definition of current

Energy stored on a capacitor

Resistance of a wire

Ohm”s law

How to add series resistors

How to add parallel resistors

Power in an electrical circuit

Magnetic force on a charge

Ampére”s law

Magnetic force on a wire

Magnetic field of a solenoid

Magnetic flux

Induced EMF

Voltage across an inductor

Energy stored in an inductor


The Internet offers some great resources for preparing for the AP Physics exam.

  • Your textbook may have an associated Web site … if so, check it out! For example, Paul A. Tipler”s Physics C-level text provides this Web site:
  • Of course, the official site of the College Board, , has administrative information and test-taking hints, as well as contact information for the organization that actually is in charge of the exam.
  • Did you enjoy your first taste of physics? If so, you can try your hand at physics debating. The United States Association for Young Physicists Tournaments hosts a national tournament which consists of “physics fights,” or debates, over experimental research projects. Check for details.
  • The author writes the country”s leading physics teaching blog, available at Students and teachers can obtain and share ideas at this site.
  • Having trouble solving calculus problems associated with Physics C, especially differential equations? Don”t spend a lot of time solving these. to get the solution spit out for you. Sure, you can”t use this on the exam, but it”s worth using on homework to speed or check your solutions. Physics is generally more about setting up the problem correctly than carrying out the mathematics anyway.