Preparing for the AP Physics 1 exam can be overwhelming, especially when it comes to memorizing all the necessary formulas. But what if you only needed a total of 15 equations to answer every question on the AP Exam?

In this blog post, we’ll cover the top 10 formulas you need to know to ace the AP Physics 1 exam. By mastering these formulas, you’ll be well on your way to understanding the underlying concepts and feeling confident on test day.

### Derivation

Memorizing formulas does not mean you will be able to solve questions. Rather, formulas aid in seeing the relationship between two or more variables. This will allow you to reach a logical conclusion. All of physics is deriving equations from fundamental equations and concepts. This is exactly what college board is testing you for.

### (1) Kinematic Formulas

The first set of formulas you need to know for AP Physics 1 are the FOUR kinematics formulas, which relate to the motion of objects. These include formulas for distance, displacement, velocity, and acceleration.

Pro-tip: If you have *more *that four formulas memorized for Kinematics, you are overstudying, and might not understand the underlying concepts.

### (2) Newton’s Laws of Motion

Newton’s laws describe the relationship between the forces acting on an object and the resulting motion of that object. They are crucial for understanding the behavior of objects in motion.

Specifically, Newton’s Second Law: **F _{net} = ma**, will allow you to solve ANY problem involving forces. This includes friction, inclines, pulley, and tension problems. This ALSO includes centripetal and torque problems!

Other useful formulas to memorize:

- friction = μN (
*force*of static or kinetic friction) - a
_{c}= v^{2}/r (centripetal acceleration)

### (3) Work-Energy Theorem

W = Fd or W = ∆KE

This theorem relates the work done on an object to its change in kinetic energy. It is essential for understanding the concepts of work and energy.

Important note: F (force) and (distance) must be parallel.

### (4) Conservation of Energy

E_{i} = E_{f}

The sum of initial types of energy = the sum of the final types of energy. This is used to solve every problem involving energy.

This principle states that energy cannot be created or destroyed, only transferred or transformed. It is crucial for understanding the conservation of energy in physical systems.

Note that energy is NOT conserved in open systems (aka a system where there are external forces).

Furthermore, note that energy is a scalar and has no direction.

### (5) Conservation of Momentum

p_{i} = p_{f}

Sum objects’ momentum *before* collision = Sum objects’ momentum *after* collision. This is used to solve every problem involving collisions in a closed systems.

Momentum is conserved in EVERY elastics and inelastic collision and in an explosion.

This principle states that the total momentum of a system remains constant if no external forces act on it. It is crucial for understanding the behavior of objects in collisions.

### (6) Impulse Theorem

Used when momentum is not conserved.

I = ∆p = m∆v = Ft

This theorem relates the force applied to an object to its resulting change in momentum. It is essential for understanding the concepts of impulse and momentum.

Important note: the most common mistake is the +/- signs on velocity. Hint: What is ∆v if a ball hits a wall at 2m/s then rebounds at the same speed?

### (7) Hooke’s Law

Technically a part of newton’s second law.

F = -kx, where k is the spring constant [how stiff a spring is] and x [how much the spring is compressed or stretched from the resting state]

Since this is a force: kx = ma

Note the negative sign is to show us that it a *restoring force*. You can ignore it in most cases.

### (8) Torque and Rotational Motion

Torque is a measure of the turning force applied to an object. Technically this is also a part of newton’s second law.

Torque = Iα = Fd

- I = rotational inertia. Every object will have its own formula. Rotational inertia of a point mass = mr2
- Force and distance have to be perpendicular

Note that ALL linear formulas mentioned previously can be converted to rotational formulas. So you don’t have to memorize any other formula for this section.

### (9) Gravitational force

This is the force between any two object. Two planets. A mass on a planet. A satellite and planet.

F_{g} = Gm_{1}m_{2}/r^{2}

This is another example of newton’s second law (forces). It can be used in combination of other forces or even centripetal acceleration (in the case of satellites).

### (10) Simple Harmonic Motion

Period (measure in seconds) is the time taken to make one complete oscillation.

Frequency (measured in 1/seconds aka hertz) is the number of oscillations in one second.

T_{spring} = 2π √(m/k)

T_{pendulum} = 2π √(L/g)

### Real-World Applications:

Beyond the AP Physics 1 exam, understanding these formulas has real-world applications. Physics is a fundamental science that helps us understand the world around us, from the motion of objects to the behavior of light. By understanding these formulas, you’ll be able to apply physics principles to solve real-world problems, from designing cars to launching satellites.