AP Physics 1 Review *2026* (Full Content Breakdown!)

This section introduces the ultimate crash course for AP Physics 1, emphasizing key test-taking tips to help students succeed. These include identifying the question first, scanning graphics with intent, knowing relevant equations and concepts, utilizing diagrams, and effective use of scratch paper for detailed problem-solving. Specific advice is given for both multiple-choice and free-response questions, such as ranking FRQs by difficulty (Easy, Medium, Hard) and writing down pertinent concepts to secure partial credit.

The kinematics section begins by defining essential terms like scalar (magnitude only) and vector (magnitude and direction), and their corresponding units. Scalar examples include time, speed, and distance, which are always positive. Vector examples include velocity, displacement, and acceleration, which can be positive or negative depending on direction. The discussion progresses to constant motion, explaining the simplified kinematic equation (ΔX = VT), and interpreting position-time, velocity-time, and acceleration-time graphs for constant velocity scenarios. It then covers acceleration, detailing its definition as the rate of velocity change (m/s²), the three ways to accelerate (speed up, slow down, change direction), and analyzing corresponding graphs for accelerating motion. Three main kinematic formulas are presented, emphasizing the strategy of identifying three known variables to solve for a fourth unknown, and the importance of drawing diagrams and isolating variables algebraically.

This part focuses on free fall motion, where objects are only influenced by gravity. Key concepts include objects slowing down when rising (positive velocity, negative acceleration), reaching zero instantaneous velocity at their peak, and speeding up when falling (negative velocity, negative acceleration). The acceleration due to gravity is established as -9.8 m/s². The section then transitions to projectile motion, a two-dimensional case. It emphasizes breaking initial velocity into horizontal (Vx) and vertical (Vy) components using trigonometry. The crucial distinction is that horizontal velocity remains constant (no horizontal forces), while vertical velocity is affected by gravity (accelerated motion). A problem-solving strategy involves setting up X and Y columns for variables, using constant velocity equations for X and acceleration equations for Y, with time being the link between the two. Vector addition is introduced for combining components to find resultant velocities.

This segment introduces Newton's First Law (Law of Inertia), stating that an object maintains its state of motion (constant velocity or rest) unless an unbalanced force acts on it. Inertia is defined as a property of mass to resist changes in motion; more mass means more inertia. Examples like sudden car braking or turning illustrate how perceived forces are often due to inertia. Newton's Third Law is then discussed as 'every force has an equal and opposite force,' always occurring in pairs simultaneously. The key point is that these forces act on different objects, preventing them from canceling each other out. Examples include pushing a box and a rocket expelling gas. The importance of analyzing forces acting on a single object is highlighted for clear understanding.

This section details common forces encountered in physics, including force of gravity (always straight down), tension (pulling force from ropes), applied force (general pushes or pulls not categorized as tension), normal force (perpendicular support force from surfaces), and friction (opposing slides, categorized into kinetic and static). It explains that static friction is generally greater than kinetic friction. The utility of force diagrams and free-body diagrams is demonstrated, showing how to represent forces acting on an object for various scenarios, such as a suspended box, a block on a ramp, or a pulled object. The importance of isolating the object of interest for analysis is stressed.

Newton's Second Law (F_net = ma) is presented as the cornerstone of dynamics problem-solving. The concept of net force is explored by analyzing forces along horizontal (X) and vertical (Y) axes. For an object resting on a flat surface, vertical forces (normal force and gravity) often balance to zero. The section then tackles more complex scenarios: an object pulled at an angle requires breaking the applied force into X and Y components using trigonometry. Objects on inclined planes demand a tilted coordinate system aligned with the ramp, decomposing gravitational force into parallel and perpendicular components. Pulley systems are analyzed by considering forces on individual masses and the entire system, emphasizing the consistent acceleration across the system. The segment concludes with a brief mention of Hooke's Law (F_spring = -kx) for springs and the connection between acceleration from Newton's Second Law and kinematic equations.

This section covers uniform circular motion, where an object moves at constant speed but with continuously changing velocity due to constant direction change. The velocity vector is always tangent to the circular path. The concept of centripetal force is introduced as a center-seeking force responsible for this motion, and it's clarified that centripetal force is not a new force but often a familiar force (like gravity, friction, or tension) acting towards the center. Because velocity is changing, objects in circular motion are accelerating, experiencing centripetal acceleration (v²/r). Problem-solving involves applying Newton's Second Law with centripetal acceleration, making forces directed towards the center positive. Key formulas include velocity (2πr/T, where T is the period) and its substitution into the centripetal acceleration formula. Examples include a roller coaster loop, a car turning, and a tetherball, illustrating how to set up force equations based on the direction of forces relative to the circle's center.

This segment introduces Newton's Universal Law of Gravitation, stating that all masses attract each other with a force directly proportional to their masses and inversely proportional to the square of the distance between their centers (F_g = (G m1 m2)/r²). The gravitational constant G is provided. The section emphasizes understanding the relationships: doubling mass doubles force, while doubling separation distance reduces force to one-fourth. Combinations of mass and distance changes are also discussed. The concept of 'little g' (gravitational acceleration) is tied into this law, showing how it can be calculated for any celestial body by canceling out the mass of the smaller object. Finally, orbital mechanics are explored, specifically the motion of a moon or satellite around a planet. The force of gravity acts as the centripetal force, allowing for the derivation of orbital velocity or period. It highlights that the mass of the orbiting object cancels out, simplifying calculations for orbital parameters.

The energy overview starts with kinetic energy (1/2 mv²), the energy of motion, highlighting its direct relationship with mass and a squared relationship with velocity. Gravitational potential energy (mgh) and elastic potential energy (1/2 kx²) are then explained, with 'h' and 'x' being the primary variables, respectively. A less common but important gravitational potential energy formula (-Gmm/r) is mentioned for scenarios with changing 'g' values. The core concept of work is defined as the transfer of energy, calculated as force multiplied by distance times the cosine of the angle between them (W = Fd cosθ). Power is then introduced as the rate at which work is done (Power = Work/time), measured in Watts (Joules per second).

This section emphasizes the critical step of defining the system for energy problems. Different system definitions (e.g., block + ramp + Earth vs. block + Earth) change how external work is accounted for. The conservation of energy principle (E_initial + W = E_final) is presented, where W accounts for work added or subtracted from the system. A roller coaster example illustrates total mechanical energy (sum of kinetic and potential energies) conservation in an ideal, closed system without non-conservative forces like air resistance or friction. The distribution of kinetic and gravitational potential energy at different points on the track is analyzed, showing their inverse relationship while total mechanical energy remains constant. The segment concludes with a detailed walk-through of a complex energy problem involving kinetic, gravitational potential, and elastic potential energies, plus work done by friction. The problem-solving strategy involves identifying initial and final energy types, expanding them into formulas, and algebraically solving for unknowns.

This segment defines momentum (p) as mass times velocity (p = mv), representing an object's amount of motion or 'inertia in motion,' with units of kg·m/s. Impulse (Δp or J) is defined as the change in momentum, which can be calculated as final momentum minus initial momentum (m(Vf - V0)) or as force multiplied by the change in time (FΔt). Key relationships are highlighted: increasing impact time decreases force for a given impulse, and increasing force or impact time increases impulse and thus velocity change. Graphical analysis of force versus time (F-t) graphs is introduced, where the area under the curve represents impulse. The discussion then moves to closed versus open systems, emphasizing that momentum is conserved in a closed system (no external forces). Two types of collisions, elastic (momentum AND kinetic energy conserved) and inelastic (momentum conserved, but kinetic energy NOT conserved), are defined. Perfect inelastic collisions are characterized by objects sticking together and combining masses. A detailed example of a collision between two spheres demonstrates how to calculate final velocity using conservation of momentum, how to determine if the collision is elastic or inelastic by checking kinetic energy conservation, and how impulse calculations for each object are equal in magnitude but opposite in direction.

This section introduces Simple Harmonic Motion (SHM) exemplified by pendulums and mass-spring systems. Key traits of SHM include a restorative force proportional to displacement, meaning the force pulling it back to equilibrium increases with greater displacement. A crucial characteristic is that the period (time for one cycle) is independent of the amplitude. Formulas for the period of a pendulum (T = 2π√(L/g)) and a mass-spring system (T = 2π√(m/k)) are provided. For the pendulum, various points in its swing are analyzed: at maximum displacement (A and C), velocity is zero, and restorative force and acceleration are maximum. At the equilibrium position (B), velocity is maximum, and restorative force and acceleration are minimum (zero). Energy transformations within the pendulum are graphically analyzed, showing kinetic energy (KE) and gravitational potential energy (UG) oscillating inversely, while total mechanical energy (TME) remains constant. For the oscillating spring, position-time, velocity-time, and acceleration-time graphs are constructed. This graphical analysis illustrates how velocity and acceleration change throughout the cycle, emphasizing phase differences and the direct relationship between restorative force and acceleration (F = -kx).

This segment introduces rotational motion by contrasting translational versus angular variables. Translational motion (linear movement) uses familiar terms like displacement (S), velocity (v), and acceleration (a). Angular motion (rotation around an internal axis) uses angular displacement (θ in radians), angular velocity (ω in rad/s), and angular acceleration (α in rad/s²). Translational kinematic equations are adapted for rotational motion by substituting angular variables. Torque (τ) is introduced as the rotational equivalent of force, defined as force times the lever arm (distance from axis of rotation) times sin(θ) (τ = Fr sinθ). Crucially, only the component of force perpendicular to the lever arm causes rotation. Examples of torque include a wrench tightening a bolt and a balanced plank (zero net torque, balancing clockwise and counter-clockwise torques). The moment of inertia (I), or rotational inertia, is also discussed, representing an object's resistance to angular acceleration. It depends on mass and how that mass is distributed relative to the axis of rotation; mass further from the axis leads to greater rotational inertia.

This section focuses on angular momentum (L) and rotational kinetic energy (KR). Angular momentum is given by L = Iω (moment of inertia times angular velocity). A key principle is that angular momentum is conserved in a closed system without external torques. This is illustrated by a figure skater: pulling arms inward decreases rotational inertia (I), causing angular velocity (ω) to increase and the skater to spin faster, while L remains constant. Rotational kinetic energy is given by KR = 1/2 Iω². The concept is applied to objects rolling down a ramp. Here, gravitational potential energy (mgh) converts into both translational kinetic energy (KT = 1/2 mv²) and rotational kinetic energy. Comparing a ring and a disc rolling down a ramp, the disc (with more mass closer to its center) has less rotational inertia, so more of the initial gravitational potential energy converts to translational kinetic energy, allowing it to reach the bottom faster than the ring. This highlights the impact of mass distribution on an object's rotational behavior and overall motion.

This overview introduces foundational concepts in fluid dynamics. Density (ρ) is defined as mass per volume (ρ = m/V), emphasizing the amount of matter packed into a given space. Fluids are characterized as gases or liquids that take the shape of their container and are often considered incompressible and non-viscous (ideal fluids). Pressure (P) is defined as force per area (P = F/A), with emphasis on the perpendicular component of molecular collisions against a container's walls. Flow rate and the continuity equation (A₁V₁ = A₂V₂) are discussed for fluids moving through pipes, demonstrating that a fluid's velocity increases in narrower sections of a pipe to maintain a constant flow rate.

The distinction between absolute pressure and gauge pressure is explained. Absolute pressure is the total pressure (total pressure = P_initial + gauge pressure), where P_initial is typically atmospheric pressure (1 atm or 101.3 kPa). Gauge pressure (ρgh) represents the pressure exerted by the fluid itself due to its depth. This is illustrated with calculating pressure at the bottom of a fluid-filled container. Buoyant force (FB) is introduced via Archimedes’ Principle: FB equals the weight of the fluid displaced by an object. Newton's Second Law is applied to analyze objects submerged in fluids, balancing buoyant force, gravitational force, and potentially tension from a string. The formula for buoyant force (FB = ρVg) is provided, where V is the volume of the submerged portion of the object.

This final part covers Bernoulli's equation, which describes the conservation of mechanical energy in a fluid flow (P + 1/2 ρV² + ρgh = constant). This equation considers pressure, kinetic energy density, and potential energy density at different points in a fluid system, such as a pipe. The importance of using the continuity equation (A₁V₁ = A₂V₂) in conjunction with Bernoulli's is noted. Torricelli's theorem, a simplified case of Bernoulli's, is then presented: the speed of efflux (exiting velocity) from an opening in a container is equal to the velocity an object would gain if dropped from the fluid's surface to the opening (V = √(2gh)). More complex scenarios, such as when initial and final pressures differ (e.g., a sealed container with higher internal pressure), require the full Bernoulli's equation for calculating efflux velocity.