How is the AP Physics 1 exam scored?

AP exams are scored on a 1–5 scale. The multiple-choice and free-response sections each contribute 50% of the score, which is then converted to the 1–5 AP score. A 3 or higher is generally considered passing and may earn college credit, though each college sets its own credit policy.

What is a passing score on AP Physics 1?

A score of 3 or higher is generally treated as passing and is the most common threshold for college credit. Roughly half of all test-takers earn a 3 or above each year, making it one of the more challenging AP exams. Always check the specific credit policy of your target college.

What units are on the AP Physics 1 exam?

The current (2024-25 redesign) course covers eight units: Kinematics; Force and Translational Dynamics; Work, Energy, and Power; Linear Momentum; Torque and Rotational Dynamics; Energy and Momentum of Rotating Systems; Oscillations; and Fluids. The 2024-25 redesign added Unit 8: Fluids to the course.

Is Fluids on the AP Physics 1 exam?

Yes. The College Board's 2024-25 redesign of AP Physics 1 added Unit 8: Fluids — covering density, pressure, buoyancy (Archimedes' principle), and the continuity equation. It accounts for roughly 10–15% of the multiple-choice questions.

Can I use a calculator on the AP Physics 1 exam?

Yes. A four-function, scientific, or graphing calculator is permitted on both sections of the AP Physics 1 exam, and the College Board provides a formula sheet (a table of equations) for the entire test.

How should I use this AP Physics 1 study guide?

Work through the eight units in order, since each builds on the last — kinematics and forces underpin energy, momentum, and rotation. After each unit, take the checkpoint quiz to find gaps, then drill that unit with our free practice questions and flashcards before sitting a full timed practice exam.

Is this AP Physics 1 study guide free?

Yes — the full guide, the unit checkpoints, the glossary, the practice questions, and the flashcards are 100% free, with no account required.

What is the difference between speed, velocity, and acceleration?

Speed is how fast something moves (a scalar). Velocity is speed with a direction (a vector). Acceleration is the rate at which velocity changes — also a vector. An object can have constant speed yet still accelerate, because changing direction changes velocity. This is core Unit 1 (Kinematics) content. On a position-time graph the slope is velocity; on a velocity-time graph the slope is acceleration and the area under the curve is displacement. An object moving in a circle at constant speed is accelerating, because its direction — and therefore its velocity — is constantly changing.

What are the kinematic equations and when do you use them?

The kinematic equations relate displacement, velocity, acceleration, and time for motion with constant acceleration. The main ones are v = v₀ + at, x = x₀ + v₀t + ½at², and v² = v₀² + 2a·Δx. Pick the equation that contains the three knowns and the one unknown. These apply only when acceleration is constant (such as free fall near Earth's surface, where a = g ≈ 9.8 m/s²). For projectile motion, treat the horizontal and vertical directions separately — horizontal velocity stays constant while vertical motion accelerates downward.

What is Newton's second law of motion?

Newton's second law states that the net force on an object equals its mass times its acceleration: F_net = ma. The acceleration is in the same direction as the net force, and for a given force a more massive object accelerates less. This is the central relationship of Unit 2. Always sum the forces (often using a free-body diagram) to get the net force before applying it. Newton's first law (inertia) is the special case where the net force — and therefore the acceleration — is zero, so the object stays at rest or moves at constant velocity.

What is a free-body diagram and how do you draw one?

A free-body diagram shows a single object as a dot with an arrow for each force acting on it — gravity, normal force, friction, tension, applied force. The arrows point in the direction each force acts, and their lengths suggest relative magnitude. Free-body diagrams are essential for Unit 2 problems. They let you sum forces in each direction to find the net force and apply Newton's second law. Only include forces acting on the object itself — not forces the object exerts on other things, and not 'centrifugal' or imagined forces.

What is centripetal force and why does it point inward?

Centripetal force is the net inward force that keeps an object moving in a circle. It always points toward the center of the circle and has magnitude F = mv²/r. It is not a new kind of force — it is provided by gravity, tension, friction, or a normal force. Because circular motion constantly changes the direction of velocity, there must be an inward acceleration (centripetal acceleration a = v²/r), and an inward net force to cause it. There is no real outward 'centrifugal' force — the outward feeling is just inertia carrying you in a straight line while the inward force curves your path.

What is the work-energy theorem?

The work-energy theorem says the net work done on an object equals its change in kinetic energy: W_net = ΔKE = ½mv² − ½mv₀². Positive net work speeds the object up; negative net work (like friction) slows it down. Work is force times displacement in the direction of the force (W = Fd·cosθ). A force perpendicular to the motion does zero work. This is a Unit 3 cornerstone and a fast alternative to kinematics when you care about speeds rather than times.

What is conservation of mechanical energy?

When only conservative forces (like gravity or an ideal spring) do work, the total mechanical energy — kinetic plus potential — stays constant. Energy converts between forms, so KE + PE before equals KE + PE after, even though each part changes. For a dropped object, gravitational potential energy (mgh) converts entirely into kinetic energy (½mv²) by the bottom, in the absence of friction. When friction or air resistance is present, mechanical energy is not conserved — some is converted to thermal energy, so total energy (including heat) is still conserved.

What is the impulse-momentum theorem?

Impulse is the product of force and the time it acts (J = F·Δt), and it equals the change in momentum: F·Δt = Δp = mΔv. So spreading a collision over a longer time reduces the force, which is why airbags, crumple zones, and bending your knees on landing help. Momentum p = mv is a vector. The impulse-momentum theorem links the force during a collision to how much the momentum changes. For a fixed change in momentum, a larger Δt means a smaller force — the basis of most safety design questions on Unit 4.

What is the difference between an elastic and an inelastic collision?

In both elastic and inelastic collisions, total momentum is conserved (no external force). The difference is kinetic energy: in an elastic collision total kinetic energy is conserved, while in an inelastic collision some kinetic energy is converted to heat, sound, or deformation. A perfectly inelastic collision is the extreme case where the objects stick together and move as one — the most kinetic energy possible is lost. Always start collision problems by writing conservation of momentum; add a kinetic-energy equation only if the collision is stated to be elastic.

What is torque and how is it calculated?

Torque is the rotational equivalent of force — the twisting effect that makes an object rotate. It equals the force times the lever arm (the perpendicular distance from the axis to the line of the force): τ = r·F·sinθ. A larger lever arm gives more torque for the same force. Torque is central to Unit 5. An object is in rotational equilibrium when the net torque on it is zero, which is how seesaw and balanced-beam problems are solved. Newton's second law for rotation is τ_net = Iα, where I is the moment of inertia and α is the angular acceleration.

What is moment of inertia?

Moment of inertia is an object's resistance to changes in its rotation — the rotational analog of mass. It depends not only on how much mass an object has but on how that mass is distributed: mass farther from the axis gives a larger moment of inertia. For the same total mass, a hoop (mass on the rim) has a larger moment of inertia than a solid disk (mass spread inward), so it is harder to spin up. In Newton's rotational second law (τ = Iα), moment of inertia plays the role mass plays in F = ma.

What is conservation of angular momentum?

When no external torque acts on a system, its angular momentum (L = Iω) stays constant. So if the moment of inertia decreases, the angular velocity must increase to keep L the same — the reason a spinning skater speeds up when she pulls her arms in. This is the rotational analog of conservation of linear momentum and a key Unit 6 idea. Rotational kinetic energy is ½Iω². When a skater pulls her arms in, her rotational KE actually increases because she does work pulling her arms inward.

What is rolling without slipping?

Rolling without slipping is motion where a round object's contact point does not slide along the surface. The condition links translation and rotation: the center's speed equals the radius times the angular velocity, v = rω, and the total kinetic energy is translational plus rotational. When a ball or disk rolls down a ramp, gravitational potential energy splits between translational KE (½mv²) and rotational KE (½Iω²). Because some energy goes into spinning, a rolling object reaches the bottom slower than the same object sliding frictionlessly.

What is simple harmonic motion?

Simple harmonic motion is back-and-forth oscillation in which the restoring force is proportional to displacement and points back toward equilibrium (F = −kx). A mass on a spring and a small-angle pendulum are the standard examples; their position traces a sine curve over time. In SHM, speed is greatest at equilibrium (where acceleration is zero) and zero at the extremes (where acceleration is greatest). The period of a mass-spring system, T = 2π√(m/k), depends only on mass and stiffness — not on amplitude. A pendulum's period, T = 2π√(L/g), depends only on length and gravity.

What is Archimedes' principle and the buoyant force?

Archimedes' principle states that the upward buoyant force on an object in a fluid equals the weight of the fluid it displaces: F_b = ρ·V·g, where ρ is the fluid's density and V is the submerged volume. An object floats when this force is at least equal to its weight. Buoyancy is a Unit 8 (Fluids) concept, added in the 2024-25 redesign of AP Physics 1. An object floats if it is less dense than the fluid and sinks if it is denser. A floating object displaces a weight of fluid exactly equal to its own weight.

What is the continuity equation for fluids?

The continuity equation says that for an incompressible fluid in steady flow, the volume flow rate is constant: A₁v₁ = A₂v₂. Where a pipe narrows (smaller area A), the fluid must speed up; where it widens, the fluid slows down. This is a Unit 8 (Fluids) idea. It explains why water speeds up when you pinch the end of a hose. Paired with Bernoulli's principle (faster-moving fluid has lower pressure), it accounts for lift and many fluid-flow questions.

What is the difference between mass and weight?

Mass is the amount of matter in an object and is the same everywhere (measured in kilograms). Weight is the gravitational force on that mass, W = mg, and changes with the local gravitational field — you weigh less on the Moon even though your mass is unchanged. Mass measures inertia (resistance to acceleration); weight is a force measured in newtons. On Earth's surface, g ≈ 9.8 m/s² (often approximated as 10 m/s² for quick estimates on the exam).

A quantity with magnitude only and no direction — such as speed, distance, mass, energy, or time.

A quantity with both magnitude and direction — such as velocity, acceleration, force, or momentum. Vectors add by components or head-to-tail.

The straight-line change in position of an object, including direction. It is a vector, unlike distance, which is the total path length.

The rate of change of position with direction (a vector). Average velocity is displacement divided by time.

The rate of change of velocity. Because velocity is a vector, an object accelerates whenever its speed or its direction changes.

Motion under gravity alone, with no air resistance. Near Earth's surface every object in free fall accelerates downward at g ≈ 9.8 m/s².

Two-dimensional motion under gravity. The horizontal velocity stays constant while the vertical motion accelerates downward; the two directions are analyzed separately.

The law of inertia: an object stays at rest or moves at constant velocity unless acted on by a net external force.

The net force on an object equals its mass times its acceleration: $F_{net} = ma$.

For every force one object exerts on a second, the second exerts an equal and opposite force on the first. The pair acts on different objects.

A sketch showing a single object and every force acting on it as a labeled arrow, used to find the net force.

The support force a surface exerts perpendicular to itself on an object pressing against it.

A force that opposes relative motion (or attempted motion) between surfaces in contact. Kinetic friction acts on sliding surfaces; static friction resists the start of sliding.

The gravitational force on an object's mass: $W = mg$. It is a force (in newtons) and changes with the local gravitational field.

The amount of matter in an object and a measure of its inertia. Mass is the same everywhere; unlike weight, it does not depend on gravity.

The net inward force that keeps an object moving in a circle, with magnitude $F = \dfrac{mv^2}{r}$, directed toward the center.

Centripetal acceleration

The inward acceleration of an object in circular motion, $a = \dfrac{v^2}{r}$, caused by the continual change in the direction of velocity.

The energy of motion: $KE = \tfrac{1}{2}mv^2$. It depends on the square of the speed, so doubling speed quadruples kinetic energy.

Stored energy of position or configuration. Gravitational PE is $mgh$; elastic (spring) PE is $\tfrac{1}{2}kx^2$.

The net work done on an object equals its change in kinetic energy: $W_{net} = \Delta KE$.

The rate at which work is done or energy is transferred: $P = \dfrac{W}{t} = Fv$. Measured in watts (W).

The product of an object's mass and velocity, $p = mv$. It is a vector and is conserved when no external force acts.

The product of a force and the time it acts, $J = F\Delta t$, equal to the change in momentum ($J = \Delta p$).

FREE AP Physics 1 Study Guide 2026 + Readiness Score

This free AP Physics 1 study guide teaches to the current College Board AP Physics 1: Algebra-Based course — every unit the exam tests, organized the way the course is built.^[1] AP Physics 1 is an algebra-based, first-year college physics course; the exam earns a 1–5 score, and a 3 or higher generally qualifies for college credit.^[2]

The course was redesigned for 2024-25, which added and reorganized the material into eight units. This guide covers all eight — from and through energy, momentum, rotation, oscillations, and fluids. It’s interactive, not a wall of text: every unit has a built-in checkpoint quiz, hover-able glossary terms, worked examples, free-body diagrams, and concept questions, so you learn by doing.

Read this guide unit by unit — they build on each other, so master kinematics and forces before energy and momentum. Test yourself at each checkpoint, then round out your free AP Physics 1 prep with our practice questions and flashcards.

AP Physics 1 is one of the 17 AP exams — explore our AP study guides to compare and prep across the whole family.

AP Physics 1 Exam Snapshot

AP Physics 1 exam at a glance (2026)
Detail	AP Physics 1: Algebra-Based
Questions	40 multiple choice (Section I) + 4 free response (Section II)
Section weighting	Multiple choice 50% · free response 50%
Total time	About 3 hours (80 min MC + 100 min FRQ, plus a break)
Score scale	1–5 (3 or higher generally earns college credit)
Units	8 units (2024-25 redesign added Unit 8: Fluids)
Calculator	Four-function, scientific, or graphing — allowed on both sections
Formula sheet	Provided (a table of equations for the whole exam)
Course type	Algebra-based, first-year college physics
Publisher	College Board

How the AP Physics 1 exam is built — two equal halves

The multiple-choice section and the free-response section are each worth 50% of your final AP score. Total exam time is about 3 hours.

Section I — Multiple Choice (50% of score)40 questions · 80 minutes. Single-select questions across all 8 units. A four-function, scientific, or graphing calculator is allowed on the whole exam, and a formula sheet is provided.
10-minute break — a short pause
Section II — Free Response (50% of score)4 questions · 100 minutes. The redesigned FRQ types: Mathematical Routines, Translation Between Representations, Experimental Design and Analysis, and Qualitative/Quantitative Translation. You show reasoning and justify answers.

Scored 1–5; a 3 or higher is generally considered passing and may earn college credit. Roughly half of test-takers score a 3+ each year.

AP Physics 1 is widely regarded as one of the tougher AP exams — historically only about half of test-takers earn a 3 or higher.^[3] The good news is that the content is highly cumulative and formula-driven: a few core relationships ( $F = ma$ , the , and ) reappear across many units. Spend your study time where the points are — Forces and Energy together are roughly 40% of the multiple-choice section:

AP Physics 1 units by approximate multiple-choice weight (2026)

Force & Translational Dynamics23% · ~18–23% (Unit 2)

Work, Energy & Power23% · ~18–23% (Unit 3)

Kinematics15% · ~10–15% (Unit 1)

Linear Momentum15% · ~10–15% (Unit 4)

Torque & Rotational Dynamics15% · ~10–15% (Unit 5)

Fluids15% · ~10–15% (Unit 8)

Energy & Momentum of Rotating Systems8% · ~5–8% (Unit 6)

Oscillations8% · ~5–8% (Unit 7)

College Board reports unit weights as approximate ranges, so the exact mix shifts slightly each year.^[1] This guide teaches all eight units in their official order as eight study modules.

Unit 1 · Kinematics

About 10–15% of the multiple-choice section. Kinematics is the description of motion — without yet asking what causes it. You work with , , and , read motion graphs, and analyze projectiles.^[1]

Describing Motion & Graphs

First, distinguish a (magnitude only, like speed or distance) from a (magnitude and direction, like velocity or displacement). Then read graphs carefully: on a position-time graph the slope is velocity; on a velocity-time graph the slope is acceleration and the area under the curve is displacement.

The Kinematic Equations

For motion with constant acceleration, three equations connect displacement, velocity, acceleration, and time:

The constant-acceleration kinematic equations
Equation	Use it when you know...
$v = v_0 + at$	Initial velocity, acceleration, time → final velocity
$x = x_0 + v_0 t + \tfrac{1}{2}at^2$	Initial velocity, acceleration, time → position
$v^2 = v_0^2 + 2a\,\Delta x$	Velocities and acceleration but NOT time → displacement

Projectile & 2-D Motion

For , the key insight is that the horizontal and vertical directions are independent. Horizontal velocity is constant (no horizontal force); vertical motion is with $a = g \approx 9.8\ \text{m/s}^2$ downward. Solve each direction with its own kinematic equations, linked only by the shared time.

Checkpoint · Unit 1 · Kinematics

Question 1 of 10

A car accelerates uniformly from $12\ \text{m/s}$ to $30\ \text{m/s}$ in $6.0\ \text{s}$ . How far does it travel during this time?

Unit 2 · Force & Translational Dynamics

About 18–23% of the multiple-choice section — the single heaviest unit. Dynamics asks whymotion happens. Master Newton’s laws and free-body diagrams here and you unlock most of the exam.^[1]

Newton’s Three Laws

(inertia): with zero net force, an object stays at rest or moves at constant velocity. is the workhorse: $F_{net} = ma$ . : forces come in equal, opposite pairs that act on different objects.

Force Types & Free-Body Diagrams

Every dynamics problem starts with a : draw the object as a dot and every force as an arrow — ( $mg$ ), , , tension, and any applied force. Then sum forces in each direction and apply $F_{net} = ma$ .

Free-body diagram — a block held by friction on a ramp

A free-body diagram shows every force on one object as an arrow. Resolve weight into components along and perpendicular to the ramp, then apply Newton’s second law in each direction.

Don’t confuse (matter / inertia, the same everywhere) with (the gravitational force $W = mg$ , which changes with the gravitational field).

Circular Motion & Gravitation

An object moving in a circle accelerates inward, even at constant speed, because its direction keeps changing. The inward () acceleration is $a = \dfrac{v^2}{r}$ , requiring a net inward $F = \dfrac{mv^2}{r}$ . Newton’s law of gravitation, $F = \dfrac{Gm_1 m_2}{r^2}$ , supplies that force for orbits.

Checkpoint · Unit 2 · Force & Translational Dynamics

Question 1 of 10

A net force of $24\ \text{N}$ acts on a $6.0\ \text{kg}$ cart on a frictionless surface. What is the magnitude of the cart's acceleration?

Unit 3 · Work, Energy & Power

About 18–23% of the multiple-choice section — tied for heaviest. Energy methods give you a powerful shortcut: when you care about speeds rather than times, conservation of energy beats kinematics.^[1]

Work & Kinetic Energy

is energy transferred by a force through a displacement, $W = Fd\cos\theta$ — a force perpendicular to the motion does zero work. The ties work to speed: $W_{net} = \Delta KE = \tfrac{1}{2}mv^2 - \tfrac{1}{2}mv_0^2$ .

Potential Energy & Conservation

is stored energy: gravitational $PE = mgh$ and elastic (spring) $PE = \tfrac{1}{2}kx^2$ . When only conservative forces act, : KE + PE before equals KE + PE after.

Conservation of mechanical energy — a dropped ball (no friction)

At the top

All potential energy, zero speed

Halfway down

Energy split evenly

Just before landing

All kinetic energy, max speed

Total mechanical energy (KE + PE) stays constant when only gravity does work. Potential energy converts to kinetic energy, but their sum is unchanged.

Power

is the rate of doing work or transferring energy, $P = \dfrac{W}{t} = Fv$ , measured in watts. Two engines doing the same work differ in power if one does it faster.

Checkpoint · Unit 3 · Work, Energy & Power

Question 1 of 10

Which expression correctly gives the translational kinetic energy of an object of mass $m$ moving with speed $v$ ?

Unit 4 · Linear Momentum

About 10–15% of the multiple-choice section. Momentum is the master tool for collisions and explosions, where forces are large but brief and hard to measure directly.^[1]

Momentum & Impulse

is $p = mv$ (a vector). is force × time and equals the change in momentum: $J = F\Delta t = \Delta p$ . So for a fixed change in momentum, spreading the collision over more time lowers the force.

Conservation of Momentum

: with no net external force, total momentum before equals total momentum after. This is your first equation for any collision or explosion.

Conservation of momentum — total p is the same before and after

Before

Cart A · 2 kg → 3 m/sCart B · 1 kg · at rest

Total momentum = (2)(3) + (1)(0) = 6 kg·m/s

After

Combined 3 kg moves at 2 m/s → total momentum = (3)(2) = 6 kg·m/s

With no external force, total momentum is conserved. Kinetic energy is not conserved in an inelastic collision — some converts to heat and deformation.

Elastic & Inelastic Collisions

In every collision momentum is conserved. The difference is kinetic energy: an conserves total KE, while an converts some KE into heat, sound, or deformation. In a perfectly inelastic collision the objects stick together.

Collision types — what is and isn't conserved
Collision type	Momentum	Kinetic energy
Elastic	Conserved	Conserved (objects bounce apart)
Inelastic	Conserved	Not conserved (some lost to heat/sound)
Perfectly inelastic	Conserved	Maximum loss (objects stick together)

Checkpoint · Unit 4 · Linear Momentum

Question 1 of 10

Which expression correctly gives the linear momentum of an object of mass $m$ moving with velocity $v$ ?

Unit 5 · Torque & Rotational Dynamics

About 10–15% of the multiple-choice section. Rotation mirrors linear motion: every linear quantity has a rotational analog. Learn the analogies and the unit largely follows.^[1]

Rotational Kinematics

Angular position, (ω, in rad/s), and angular acceleration (α) obey the same kinematic equations as their linear counterparts. Linear and angular speed link through the radius: $v = r\omega$ .

Linear ↔ rotational analogies
Linear	Rotational
Position x	Angle θ
Velocity v	Angular velocity ω
Acceleration a	Angular acceleration α
Force F	Torque τ
Mass m (inertia)	Moment of inertia I
Momentum p = mv	Angular momentum L = Iω

Torque & Equilibrium

is the rotational effect of a force, $\tau = rF\sin\theta$ , where the lever arm is the perpendicular distance from the axis to the line of force. An object is in rotational equilibrium when the net torque is zero — the key to seesaw and balanced-beam problems.

Rotational Newton’s Second Law

The rotational form of $F = ma$ is $\tau_{net} = I\alpha$ , where $I$ plays the role of mass. Crucially, $I$ depends on how mass is distributed: mass farther from the axis is harder to spin up.

Checkpoint · Unit 5 · Torque & Rotational Dynamics

Question 1 of 10

A wheel starts from rest and reaches an angular velocity of $24\ \text{rad/s}$ after rotating with constant angular acceleration for $6.0\ \text{s}$ . What is the magnitude of its angular acceleration?

Unit 6 · Energy & Momentum of Rotating Systems

About 5–8% of the multiple-choice section. This unit extends energy and momentum into rotation: rotational kinetic energy, rolling, and the conservation of angular momentum.^[1]

Rotational KE & Rolling

A rotating object stores rotational kinetic energy $KE_{rot} = \tfrac{1}{2}I\omega^2$ — the rotational twin of $\tfrac{1}{2}mv^2$ . For , the contact point doesn’t slide, so $v = r\omega$ and total kinetic energy is translational plus rotational.

Angular Momentum Conservation

$L = I\omega$ is conserved when no external torque acts. So if moment of inertia drops, angular velocity must rise to keep $L$ constant — the reason a spinning skater speeds up when she pulls her arms in.

Checkpoint · Unit 6 · Energy & Momentum of Rotating Systems

Question 1 of 5

Which expression correctly gives the rotational kinetic energy of a rigid object with moment of inertia $I$ rotating with angular velocity $\omega$ ?

Unit 7 · Oscillations

About 5–8% of the multiple-choice section. Oscillations covers simple harmonic motion — the back-and-forth of a mass on a spring or a swinging pendulum.^[1]

Simple Harmonic Motion

(SHM) occurs whenever the restoring force is proportional to displacement and points back toward equilibrium, $F = -kx$ . Speed is greatest at equilibrium (where acceleration is zero) and zero at the extremes (where acceleration is greatest).

Simple harmonic motion — a mass on a spring

At maximum displacement
speed = 0 · acceleration is greatest · all energy is potential

At equilibrium (center)
speed is greatest · acceleration = 0 · all energy is kinetic

The restoring force is proportional to displacement (F = −kx), so the period depends only on mass and stiffness — never on amplitude.

Springs, Pendulums & Energy

The of a mass-spring system, $T = 2\pi\sqrt{\dfrac{m}{k}}$ , depends only on mass and stiffness. A pendulum’s period, $T = 2\pi\sqrt{\dfrac{L}{g}}$ , depends only on length and gravity. Notably, neither depends on amplitude.

Checkpoint · Unit 7 · Oscillations

Question 1 of 5

A block on a frictionless surface attached to a spring undergoes simple harmonic motion. At which point in the motion is the magnitude of the block's acceleration the greatest?

Unit 8 · Fluids

About 10–15% of the multiple-choice section. Fluids is the unit added in the 2024-25 redesign— density and pressure, buoyancy, and fluid flow. If you used an older review book, this is the part it’s missing.^[1]

Density & Pressure

is mass per unit volume, $\rho = \dfrac{m}{V}$ . is force per unit area, $P = \dfrac{F}{A}$ . In a static fluid, gauge pressure rises with depth: $P = \rho g h$ .

Buoyancy & Archimedes’ Principle

The upward equals the weight of the fluid displaced: $F_b = \rho V g$ (Archimedes’ principle). An object floats when it is less dense than the fluid and sinks when it is denser.

Buoyant force & Archimedes’ principle (Unit 8: Fluids)

The buoyant force equals the weight of the fluid the object displaces (F = ρ·V·g). An object floats when buoyant force ≥ weight — i.e. when it is less dense than the fluid.

Fluid Flow

For an incompressible fluid in steady flow, the $A_1 v_1 = A_2 v_2$ says the volume flow rate is constant — a narrower pipe forces faster flow. Bernoulli’s principle adds that faster-moving fluid has lower pressure.

Checkpoint · Unit 8 · Fluids

Question 1 of 10

A solid block has a mass of $480\ \text{g}$ and a volume of $600\ \text{cm}^3$ . What is the density of the block?

How to Use This Study Guide

A study guide is a map, not the whole territory — use it alongside official College Board practice. Because AP Physics 1 is cumulative and formula-driven, the goal is to make the core relationships automatic, then practice applying them to unfamiliar situations. Reasoning and clear justification matter: the free-response section, half your score, rewards explaining the physics, not just plugging into a formula.

AP Physics 1 multiple-choice weighting by unit (2026)

2 · Force & Dynamics

18–23%

3 · Work, Energy & Power

18–23%

1 · Kinematics

10–15%

4 · Linear Momentum

10–15%

5 · Torque & Rotational Dyn.

10–15%

8 · Fluids

10–15%

6 · Energy/Momentum (Rot.)

5–8%

7 · Oscillations

5–8%

Units 2 and 3 (forces and energy) are the heaviest — together roughly 40% of the multiple-choice section. Master them first.

A study loop that actually works

1
Read a unit here
Work through one unit at a time, in order — they build on each other (forces and energy underpin momentum and rotation).
2
Take the checkpoint
The quick check at the end of each unit exposes what didn't stick.
3
Drill the gaps
Send your weak unit straight into the free practice questions and flashcards.
4
Take full, timed practice
Sit a full practice exam — including free response — to build stamina, then review every miss and write out your reasoning.

AP Physics 1 Concept Questions

Core physics concepts the AP Physics 1 exam actually measures — at least one per unit. Tap any card for a short, exam-ready answer backed by an official source (College Board), then test yourself on them as flashcards.

AP Physics 1 Glossary

Quick definitions for the terms and quantities you’ll see most across AP Physics 1:

Acceleration: The rate of change of velocity. Because velocity is a vector, an object accelerates whenever its speed or its direction changes.
Amplitude: The maximum displacement from equilibrium in an oscillation. For simple harmonic motion, the period does not depend on amplitude.
Angular momentum: The rotational analog of linear momentum, $L = I\omega$ . It is conserved when no external torque acts.
Angular velocity: How fast an object rotates, in radians per second (symbol ω). It relates to linear speed by $v = r\omega$ .
Buoyant force: The upward force a fluid exerts on a submerged or floating object, equal to the weight of the fluid displaced ( $F_b = \rho V g$ ) — Archimedes' principle.
Centripetal acceleration: The inward acceleration of an object in circular motion, $a = \dfrac{v^2}{r}$ , caused by the continual change in the direction of velocity.
Centripetal force: The net inward force that keeps an object moving in a circle, with magnitude $F = \dfrac{mv^2}{r}$ , directed toward the center.
Conservation of energy: Total energy is never created or destroyed, only converted. When only conservative forces act, mechanical energy (KE + PE) stays constant.
Conservation of momentum: When no net external force acts on a system, its total momentum stays constant — the basis for analyzing collisions and explosions.
Continuity equation: For an incompressible fluid in steady flow, the volume flow rate is constant: $A_1 v_1 = A_2 v_2$ , so a narrower pipe means faster flow.
Density: Mass per unit volume, $\rho = \dfrac{m}{V}$ . An object floats in a fluid that is denser than itself.
Displacement: The straight-line change in position of an object, including direction. It is a vector, unlike distance, which is the total path length.
Elastic collision: A collision in which both momentum and total kinetic energy are conserved; the objects bounce apart with no energy lost to heat.
Free fall: Motion under gravity alone, with no air resistance. Near Earth's surface every object in free fall accelerates downward at g ≈ 9.8 m/s².
Free-body diagram: A sketch showing a single object and every force acting on it as a labeled arrow, used to find the net force.
Friction: A force that opposes relative motion (or attempted motion) between surfaces in contact. Kinetic friction acts on sliding surfaces; static friction resists the start of sliding.
Impulse: The product of a force and the time it acts, $J = F\Delta t$ , equal to the change in momentum ( $J = \Delta p$ ).
Inelastic collision: A collision in which momentum is conserved but kinetic energy is not — some energy becomes heat, sound, or deformation. In a perfectly inelastic collision the objects stick together.
Kinetic energy: The energy of motion: $KE = \tfrac{1}{2}mv^2$ . It depends on the square of the speed, so doubling speed quadruples kinetic energy.
Mass: The amount of matter in an object and a measure of its inertia. Mass is the same everywhere; unlike weight, it does not depend on gravity.
Moment of inertia: An object's resistance to changes in rotation — the rotational analog of mass. It grows when mass is farther from the axis.
Momentum: The product of an object's mass and velocity, $p = mv$ . It is a vector and is conserved when no external force acts.
Newton's first law: The law of inertia: an object stays at rest or moves at constant velocity unless acted on by a net external force.
Newton's second law: The net force on an object equals its mass times its acceleration: $F_{net} = ma$ .
Newton's third law: For every force one object exerts on a second, the second exerts an equal and opposite force on the first. The pair acts on different objects.
Normal force: The support force a surface exerts perpendicular to itself on an object pressing against it.
Period: The time for one complete oscillation or cycle (symbol T). Its reciprocal is the frequency.
Potential energy: Stored energy of position or configuration. Gravitational PE is $mgh$ ; elastic (spring) PE is $\tfrac{1}{2}kx^2$ .
Power: The rate at which work is done or energy is transferred: $P = \dfrac{W}{t} = Fv$ . Measured in watts (W).
Pressure: Force per unit area, $P = \dfrac{F}{A}$ . In a static fluid, gauge pressure increases with depth as $P = \rho g h$ .
Projectile motion: Two-dimensional motion under gravity. The horizontal velocity stays constant while the vertical motion accelerates downward; the two directions are analyzed separately.
Rolling without slipping: Motion of a round object whose contact point does not slide, satisfying $v = r\omega$ ; its kinetic energy is translational plus rotational.
Scalar: A quantity with magnitude only and no direction — such as speed, distance, mass, energy, or time.
Simple harmonic motion: Oscillation in which the restoring force is proportional to displacement and directed back toward equilibrium ( $F = -kx$ ), producing sinusoidal motion.
Torque: The rotational effect of a force — the product of the force and its lever arm: $\tau = rF\sin\theta$ . It causes angular acceleration.
Vector: A quantity with both magnitude and direction — such as velocity, acceleration, force, or momentum. Vectors add by components or head-to-tail.
Velocity: The rate of change of position with direction (a vector). Average velocity is displacement divided by time.
Weight: The gravitational force on an object's mass: $W = mg$ . It is a force (in newtons) and changes with the local gravitational field.
Work: Energy transferred by a force acting through a displacement: $W = Fd\cos\theta$ . A force perpendicular to the motion does zero work.
Work-energy theorem: The net work done on an object equals its change in kinetic energy: $W_{net} = \Delta KE$ .

Free AP Physics 1 Study Materials & Resources

Everything you need to prepare for AP Physics 1 is free here — no paywall, no sign-up. This guide is the foundation; pair it with the rest of our free AP Physics 1 study materials for active recall, timed practice, and last-minute review:

AP Physics 1 Practice Test — exam-style questions across all eight units, with worked explanations.
AP Physics 1 Flashcards — active-recall decks for the high-yield laws, formulas, and quantities.

AP Physics 1 Study Guide FAQ

The AP Physics 1 exam has two sections. Section I is 40 multiple-choice questions in 80 minutes (50% of the score), and Section II is 4 free-response questions in 100 minutes (the other 50%). Total testing time is about 3 hours.

References

1.College Board. “AP Physics 1: Algebra-Based Course and Exam Description.” College Board. ↑
2.College Board. “AP Physics 1: Algebra-Based — AP Students.” College Board. ↑
3.College Board. “AP Physics 1: Algebra-Based Exam — AP Central.” College Board. ↑
4.College Board. “AP Physics 1 — About the Exam.” College Board. ↑

Sources for the concept answers

Every answer in the AP Physics 1 concept questions above is drawn from an official primary source:

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