1. Kinematics1.1 Scalars and Vectors in One Dimension0/01.1.1 Scalars and Vectors: What Is the Difference?1.1.2 How to Draw and Notate One-Dimensional Vectors1.1.3 Common Scalar and Vector Quantities in Kinematics1.1.4 Adding Vectors in One Dimension1.2 Displacement, Velocity, and Acceleration0/01.2.1 Modeling an Object as a Point1.2.2 Displacement: Change in Position1.2.3 Average Velocity1.2.4 Average Acceleration1.2.5 What It Means for an Object to Accelerate1.2.6 Average and Instantaneous Motion1.3 Representing Motion0/01.3.1 Different Ways to Represent Motion1.3.2 The Three Constant-Acceleration Kinematic Equations1.3.3 Free Fall Near Earth's Surface1.3.4 Position-Time Graphs and Instantaneous Velocity1.3.5 Velocity-Time Graphs: Slope and Area1.3.6 Acceleration-Time Graphs and Change in Velocity1.3.7 AP Physics 1 Limits for Motion Analysis1.4 Reference Frames and Relative Motion0/01.4.1 What a Reference Frame Does1.4.2 Converting Measurements Between Reference Frames1.4.3 Relative Velocity in One Dimension1.4.4 Inertial Frames and Relative Motion Limits1.5 Vectors and Motion in Two Dimensions0/01.5.1 Resultant Vectors and Perpendicular Components1.5.2 Choosing a Coordinate System for Components1.5.3 Using Trigonometry to Resolve Vectors1.5.4 Breaking Two-Dimensional Motion into Components1.5.5 Projectile Motion as Two-Dimensional Motion1. Kinematics1.1 Scalars and Vectors in One Dimension0/01.1.1 Scalars and Vectors: What Is the Difference?1.1.2 How to Draw and Notate One-Dimensional Vectors1.1.3 Common Scalar and Vector Quantities in Kinematics1.1.4 Adding Vectors in One Dimension1.2 Displacement, Velocity, and Acceleration0/01.2.1 Modeling an Object as a Point1.2.2 Displacement: Change in Position1.2.3 Average Velocity1.2.4 Average Acceleration1.2.5 What It Means for an Object to Accelerate1.2.6 Average and Instantaneous Motion1.3 Representing Motion0/01.3.1 Different Ways to Represent Motion1.3.2 The Three Constant-Acceleration Kinematic Equations1.3.3 Free Fall Near Earth's Surface1.3.4 Position-Time Graphs and Instantaneous Velocity1.3.5 Velocity-Time Graphs: Slope and Area1.3.6 Acceleration-Time Graphs and Change in Velocity1.3.7 AP Physics 1 Limits for Motion Analysis1.4 Reference Frames and Relative Motion0/01.4.1 What a Reference Frame Does1.4.2 Converting Measurements Between Reference Frames1.4.3 Relative Velocity in One Dimension1.4.4 Inertial Frames and Relative Motion Limits1.5 Vectors and Motion in Two Dimensions0/01.5.1 Resultant Vectors and Perpendicular Components1.5.2 Choosing a Coordinate System for Components1.5.3 Using Trigonometry to Resolve Vectors1.5.4 Breaking Two-Dimensional Motion into Components1.5.5 Projectile Motion as Two-Dimensional Motion2. Force and Translational Dynamics2.1 Systems and Center of Mass0/02.1.1 Describing a System in Physics2.1.2 Modeling a System as One Object2.1.3 Systems, Environment, and Transfers2.1.4 Internal Structure and Changing Subsystems2.1.5 Finding Center of Mass2.1.6 Center of Mass as a Single-Object Model2.2 Forces and Free-Body Diagrams0/02.2.1 Forces as Interactions Between Objects2.2.2 Contact Forces and What Causes Them2.2.3 Reading and Drawing Free-Body Diagrams2.2.4 Forces as Vectors from the Center of Mass2.2.5 Choosing Axes for Easier Force Equations2.3 Newton's Third Law0/02.3.1 Newton's Third Law Force Pairs2.3.2 Internal Forces and Center-of-Mass Motion2.3.3 Tension in Ideal Strings and Pulleys2.3.4 Tension in Real Strings and AP Limits2.3.5 Action at a Distance in AP Physics 12.4 Newton's First Law0/02.4.1 Net Force as a Vector Sum2.4.2 Translational Equilibrium2.4.3 Constant Velocity and Newton's First Law2.4.4 Balanced in One Direction, Unbalanced in Another2.4.5 Inertial Reference Frames2.5 Newton's Second Law0/02.5.1 Unbalanced Forces and Motion Changes2.5.2 Newton's Second Law and Acceleration2.5.3 External Net Force and Changing Velocity2.6 Gravitational Force0/02.6.1 Universal Gravitation Between Masses2.6.2 Gravitational Fields and Field Strength2.6.3 Weight Near Earth2.6.4 When Gravity Can Be Treated as Constant2.6.5 Apparent Weight and the Normal Force2.6.6 Weightlessness and the Equivalence Principle2.6.7 Inertial Mass and Gravitational Mass2.7 Kinetic and Static Friction0/02.7.1 Kinetic Friction and Relative Motion2.7.2 What Kinetic Friction Depends On2.7.3 Normal Force and Material Properties2.7.4 Static Friction Before Sliding Starts2.7.5 Maximum Static Friction2.7.6 Comparing Static and Kinetic Friction2.8 Spring Forces0/02.8.1 Ideal Springs and Stretching2.8.2 Hooke�s Law2.8.3 Spring Force Direction and Equilibrium2.9 Circular Motion0/02.9.1 Centripetal Acceleration in Circular Motion2.9.2 Forces That Cause Circular Motion2.9.3 Minimum Speed at the Top of a Loop2.9.4 Circular Motion on Banked Curves and Conical Pendulums2.9.5 Tangential and Net Acceleration2.9.6 Period, Frequency, and Uniform Circular Motion2.9.7 Circular Orbits and Kepler's Third Law2. Force and Translational Dynamics2.1 Systems and Center of Mass0/02.1.1 Describing a System in Physics2.1.2 Modeling a System as One Object2.1.3 Systems, Environment, and Transfers2.1.4 Internal Structure and Changing Subsystems2.1.5 Finding Center of Mass2.1.6 Center of Mass as a Single-Object Model2.2 Forces and Free-Body Diagrams0/02.2.1 Forces as Interactions Between Objects2.2.2 Contact Forces and What Causes Them2.2.3 Reading and Drawing Free-Body Diagrams2.2.4 Forces as Vectors from the Center of Mass2.2.5 Choosing Axes for Easier Force Equations2.3 Newton's Third Law0/02.3.1 Newton's Third Law Force Pairs2.3.2 Internal Forces and Center-of-Mass Motion2.3.3 Tension in Ideal Strings and Pulleys2.3.4 Tension in Real Strings and AP Limits2.3.5 Action at a Distance in AP Physics 12.4 Newton's First Law0/02.4.1 Net Force as a Vector Sum2.4.2 Translational Equilibrium2.4.3 Constant Velocity and Newton's First Law2.4.4 Balanced in One Direction, Unbalanced in Another2.4.5 Inertial Reference Frames2.5 Newton's Second Law0/02.5.1 Unbalanced Forces and Motion Changes2.5.2 Newton's Second Law and Acceleration2.5.3 External Net Force and Changing Velocity2.6 Gravitational Force0/02.6.1 Universal Gravitation Between Masses2.6.2 Gravitational Fields and Field Strength2.6.3 Weight Near Earth2.6.4 When Gravity Can Be Treated as Constant2.6.5 Apparent Weight and the Normal Force2.6.6 Weightlessness and the Equivalence Principle2.6.7 Inertial Mass and Gravitational Mass2.7 Kinetic and Static Friction0/02.7.1 Kinetic Friction and Relative Motion2.7.2 What Kinetic Friction Depends On2.7.3 Normal Force and Material Properties2.7.4 Static Friction Before Sliding Starts2.7.5 Maximum Static Friction2.7.6 Comparing Static and Kinetic Friction2.8 Spring Forces0/02.8.1 Ideal Springs and Stretching2.8.2 Hooke�s Law2.8.3 Spring Force Direction and Equilibrium2.9 Circular Motion0/02.9.1 Centripetal Acceleration in Circular Motion2.9.2 Forces That Cause Circular Motion2.9.3 Minimum Speed at the Top of a Loop2.9.4 Circular Motion on Banked Curves and Conical Pendulums2.9.5 Tangential and Net Acceleration2.9.6 Period, Frequency, and Uniform Circular Motion2.9.7 Circular Orbits and Kepler's Third Law3. Work, Energy, and PowerPremium3.1 Translational Kinetic Energy0/03.1.1 What Translational Kinetic Energy Means3.1.2 How Mass and Speed Affect Kinetic Energy3.1.3 Why Kinetic Energy Is a Scalar3.1.4 Kinetic Energy and Frames of Reference3.2 Work0/03.2.1 Work as Energy Transfer3.2.2 Conservative and Nonconservative Forces3.2.3 Calculating Work from Force and Displacement3.2.4 Positive, Negative, and Zero Work3.2.5 The Work-Energy Theorem3.2.6 Configuration Changes, Friction, and Force-Displacement Graphs3.3 Potential Energy0/03.3.1 Potential Energy Belongs to a System3.3.2 Scalar Potential Energy and the Choice of Zero3.3.3 Elastic Potential Energy in an Ideal Spring3.3.4 Gravitational Potential Energy Near and Far3.3.5 Total Potential Energy in Multi-Object Systems3.4 Conservation of Energy0/03.4.1 What Energies a System Can Have3.4.2 Mechanical Energy and Energy Accounting3.4.3 Choosing a System for Conservation of Energy3.4.4 Work, Transfers, and Dissipation3.5 Power0/03.5.1 Power as the Rate of Energy Change3.5.2 Average Power from Energy Transfer3.5.3 Average Power from Work Done3.5.4 Instantaneous Power from Force and Velocity3. Work, Energy, and PowerPremium3.1 Translational Kinetic Energy0/03.1.1 What Translational Kinetic Energy Means3.1.2 How Mass and Speed Affect Kinetic Energy3.1.3 Why Kinetic Energy Is a Scalar3.1.4 Kinetic Energy and Frames of Reference3.2 Work0/03.2.1 Work as Energy Transfer3.2.2 Conservative and Nonconservative Forces3.2.3 Calculating Work from Force and Displacement3.2.4 Positive, Negative, and Zero Work3.2.5 The Work-Energy Theorem3.2.6 Configuration Changes, Friction, and Force-Displacement Graphs3.3 Potential Energy0/03.3.1 Potential Energy Belongs to a System3.3.2 Scalar Potential Energy and the Choice of Zero3.3.3 Elastic Potential Energy in an Ideal Spring3.3.4 Gravitational Potential Energy Near and Far3.3.5 Total Potential Energy in Multi-Object Systems3.4 Conservation of Energy0/03.4.1 What Energies a System Can Have3.4.2 Mechanical Energy and Energy Accounting3.4.3 Choosing a System for Conservation of Energy3.4.4 Work, Transfers, and Dissipation3.5 Power0/03.5.1 Power as the Rate of Energy Change3.5.2 Average Power from Energy Transfer3.5.3 Average Power from Work Done3.5.4 Instantaneous Power from Force and Velocity4. Linear MomentumPremium4.1 Linear Momentum0/04.1.1 What Is Linear Momentum?4.1.2 Momentum as a Vector4.1.3 Using Momentum to Study Collisions4.1.4 Using Momentum to Study Explosions4.2 Change in Momentum and Impulse0/04.2.1 Force as the Rate of Change of Momentum4.2.2 Defining Impulse4.2.3 Impulse on Graphs4.2.4 Momentum Change and the Impulse–Momentum Theorem4.2.5 Linking Impulse to Newton’s Second Law4.3 Conservation of Linear Momentum0/04.3.1 Center of Mass and System Motion4.3.2 Total Momentum of a System4.3.3 Internal Interactions and Equal-and-Opposite Impulses4.3.4 Choosing a System for Momentum Conservation4.3.5 Using Conservation in Collisions and Explosions4.4 Elastic and Inelastic Collisions0/04.4.1 What Makes a Collision Elastic?4.4.2 Kinetic Energy Distribution in Elastic Collisions4.4.3 Inelastic and Perfectly Inelastic Collisions4.4.4 Where the Lost Kinetic Energy Goes4. Linear MomentumPremium4.1 Linear Momentum0/04.1.1 What Is Linear Momentum?4.1.2 Momentum as a Vector4.1.3 Using Momentum to Study Collisions4.1.4 Using Momentum to Study Explosions4.2 Change in Momentum and Impulse0/04.2.1 Force as the Rate of Change of Momentum4.2.2 Defining Impulse4.2.3 Impulse on Graphs4.2.4 Momentum Change and the Impulse–Momentum Theorem4.2.5 Linking Impulse to Newton’s Second Law4.3 Conservation of Linear Momentum0/04.3.1 Center of Mass and System Motion4.3.2 Total Momentum of a System4.3.3 Internal Interactions and Equal-and-Opposite Impulses4.3.4 Choosing a System for Momentum Conservation4.3.5 Using Conservation in Collisions and Explosions4.4 Elastic and Inelastic Collisions0/04.4.1 What Makes a Collision Elastic?4.4.2 Kinetic Energy Distribution in Elastic Collisions4.4.3 Inelastic and Perfectly Inelastic Collisions4.4.4 Where the Lost Kinetic Energy Goes5. Torque and Rotational DynamicsPremium5.1 Rotational Kinematics0/05.1.1 Angular Displacement and Radians5.1.2 Rigid Systems and Direction Conventions5.1.3 Average Angular Velocity5.1.4 Average Angular Acceleration5.1.5 Rotational Motion and Its Linear Analogy5.1.6 Constant Angular Acceleration Equations and Graphs5.2 Connecting Linear and Rotational Motion0/05.2.1 Arc Length from Angular Displacement5.2.2 Tangential Speed and Angular Speed5.2.3 Tangential Acceleration and Angular Acceleration5.2.4 Same Rotation, Different Linear Motion5.3 Torque0/05.3.1 What Creates Torque?5.3.2 Lever Arm and Turning Effect5.3.3 Using Force Diagrams for Rigid Systems5.3.4 Calculating Torque Magnitude5.4 Rotational Inertia0/05.4.1 Rotational Inertia as Resistance to Change5.4.2 Rotational Inertia of a Single Object5.4.3 Total Rotational Inertia of a System5.4.4 Why Mass Farther from the Axis Matters5.4.5 Axes Through the Center of Mass5.4.6 Parallel Axis Theorem5.5 Rotational Equilibrium and Newton’s First Law in Rotational Form0/05.5.1 Constant Angular Velocity and Net Torque5.5.2 Rotational Equilibrium vs. Translational Equilibrium5.5.3 Using Free-Body and Force Diagrams5.5.4 Unbalanced Torque Means Changing Rotation5.6 Newton’s Second Law in Rotational Form0/05.6.1 When Angular Velocity Changes5.6.2 Net Torque, Angular Acceleration, and Rotational Inertia5.6.3 Combining Linear and Rotational Analysis5. Torque and Rotational DynamicsPremium5.1 Rotational Kinematics0/05.1.1 Angular Displacement and Radians5.1.2 Rigid Systems and Direction Conventions5.1.3 Average Angular Velocity5.1.4 Average Angular Acceleration5.1.5 Rotational Motion and Its Linear Analogy5.1.6 Constant Angular Acceleration Equations and Graphs5.2 Connecting Linear and Rotational Motion0/05.2.1 Arc Length from Angular Displacement5.2.2 Tangential Speed and Angular Speed5.2.3 Tangential Acceleration and Angular Acceleration5.2.4 Same Rotation, Different Linear Motion5.3 Torque0/05.3.1 What Creates Torque?5.3.2 Lever Arm and Turning Effect5.3.3 Using Force Diagrams for Rigid Systems5.3.4 Calculating Torque Magnitude5.4 Rotational Inertia0/05.4.1 Rotational Inertia as Resistance to Change5.4.2 Rotational Inertia of a Single Object5.4.3 Total Rotational Inertia of a System5.4.4 Why Mass Farther from the Axis Matters5.4.5 Axes Through the Center of Mass5.4.6 Parallel Axis Theorem5.5 Rotational Equilibrium and Newton’s First Law in Rotational Form0/05.5.1 Constant Angular Velocity and Net Torque5.5.2 Rotational Equilibrium vs. Translational Equilibrium5.5.3 Using Free-Body and Force Diagrams5.5.4 Unbalanced Torque Means Changing Rotation5.6 Newton’s Second Law in Rotational Form0/05.6.1 When Angular Velocity Changes5.6.2 Net Torque, Angular Acceleration, and Rotational Inertia5.6.3 Combining Linear and Rotational Analysis6. Energy and Momentum of Rotating SystemsPremium6.1 Rotational Kinetic Energy0/06.1.1 Understanding Rotational Kinetic Energy6.1.2 Rotational and Translational Kinetic Energy Together6.1.3 Rotation When the Center of Mass Is at Rest6.2 Torque and Work0/06.2.1 How Torque Transfers Energy6.2.2 Calculating Work Done by a Torque6.2.3 Using Torque–Position Graphs6.3 Angular Momentum and Angular Impulse0/06.3.1 Angular Momentum of a Rotating Rigid System6.3.2 Angular Momentum of a Moving Object About a Point6.3.3 Why the Choice of Axis Matters6.3.4 Angular Impulse from Torque and Time6.3.5 Relating Angular Impulse to Change in Angular Momentum6.3.6 Graphs of Torque and Angular Momentum6.3.7 AP Physics 1 Scope for Angular Momentum6.4 Conservation of Angular Momentum0/06.4.1 Total Angular Momentum in a System6.4.2 When a System's Angular Momentum Can Change6.4.3 Equal and Opposite Angular Impulses6.4.4 Spinning Faster by Changing Shape6.4.5 Choosing the Right System for Conservation6.5 Rolling0/06.5.1 Total Kinetic Energy in Rolling Motion6.5.2 Rolling Without Slipping6.5.3 Friction in Ideal Rolling6.5.4 Rolling While Slipping6.5.5 What AP Physics 1 Expects for Slipping Motion6.6 Motion of Orbiting Satellites0/06.6.1 A Satellite Orbiting a Much More Massive Object6.6.2 Conservation Laws in Satellite Motion6.6.3 Circular Orbits6.6.4 Elliptical Orbits6.6.5 Gravitational Potential Energy and Infinity6.6.6 Escape Velocity6.6.7 What Happens After Reaching Escape Velocity6. Energy and Momentum of Rotating SystemsPremium6.1 Rotational Kinetic Energy0/06.1.1 Understanding Rotational Kinetic Energy6.1.2 Rotational and Translational Kinetic Energy Together6.1.3 Rotation When the Center of Mass Is at Rest6.2 Torque and Work0/06.2.1 How Torque Transfers Energy6.2.2 Calculating Work Done by a Torque6.2.3 Using Torque–Position Graphs6.3 Angular Momentum and Angular Impulse0/06.3.1 Angular Momentum of a Rotating Rigid System6.3.2 Angular Momentum of a Moving Object About a Point6.3.3 Why the Choice of Axis Matters6.3.4 Angular Impulse from Torque and Time6.3.5 Relating Angular Impulse to Change in Angular Momentum6.3.6 Graphs of Torque and Angular Momentum6.3.7 AP Physics 1 Scope for Angular Momentum6.4 Conservation of Angular Momentum0/06.4.1 Total Angular Momentum in a System6.4.2 When a System's Angular Momentum Can Change6.4.3 Equal and Opposite Angular Impulses6.4.4 Spinning Faster by Changing Shape6.4.5 Choosing the Right System for Conservation6.5 Rolling0/06.5.1 Total Kinetic Energy in Rolling Motion6.5.2 Rolling Without Slipping6.5.3 Friction in Ideal Rolling6.5.4 Rolling While Slipping6.5.5 What AP Physics 1 Expects for Slipping Motion6.6 Motion of Orbiting Satellites0/06.6.1 A Satellite Orbiting a Much More Massive Object6.6.2 Conservation Laws in Satellite Motion6.6.3 Circular Orbits6.6.4 Elliptical Orbits6.6.5 Gravitational Potential Energy and Infinity6.6.6 Escape Velocity6.6.7 What Happens After Reaching Escape Velocity7. OscillationsPremium7.1 Defining Simple Harmonic Motion (SHM)0/07.1.1 What Makes Motion Simple Harmonic?7.1.2 Restoring Force and Equilibrium Position7.1.3 Small-Angle Pendulums as SHM7.2 Frequency and Period of SHM0/07.2.1 Relating Frequency and Period7.2.2 Period of a Mass-Spring Oscillator7.2.3 Period of a Small-Angle Pendulum7.3 Representing and Analyzing SHM0/07.3.1 Describing Displacement in SHM7.3.2 Velocity and Acceleration in the Cycle7.3.3 Using Key Positions and Times7.3.4 How Amplitude Affects Period7.3.5 Reading SHM Graphs7.4 Energy of Simple Harmonic Oscillators0/07.4.1 Total Mechanical Energy in SHM7.4.2 Conservation of Energy in SHM7.4.3 When Kinetic Energy Is Maximum7.4.4 When Potential Energy Is Maximum7.4.5 How Amplitude Changes Total Energy7. OscillationsPremium7.1 Defining Simple Harmonic Motion (SHM)0/07.1.1 What Makes Motion Simple Harmonic?7.1.2 Restoring Force and Equilibrium Position7.1.3 Small-Angle Pendulums as SHM7.2 Frequency and Period of SHM0/07.2.1 Relating Frequency and Period7.2.2 Period of a Mass-Spring Oscillator7.2.3 Period of a Small-Angle Pendulum7.3 Representing and Analyzing SHM0/07.3.1 Describing Displacement in SHM7.3.2 Velocity and Acceleration in the Cycle7.3.3 Using Key Positions and Times7.3.4 How Amplitude Affects Period7.3.5 Reading SHM Graphs7.4 Energy of Simple Harmonic Oscillators0/07.4.1 Total Mechanical Energy in SHM7.4.2 Conservation of Energy in SHM7.4.3 When Kinetic Energy Is Maximum7.4.4 When Potential Energy Is Maximum7.4.5 How Amplitude Changes Total Energy8. FluidsPremium8.1 Internal Structure and Density0/08.1.1 States of Matter and Particle Interactions8.1.2 What Makes a Substance a Fluid?8.1.3 Density as Mass per Unit Volume8.1.4 Ideal Fluids: Incompressible and Nonviscous8.2 Pressure0/08.2.1 Pressure from a Perpendicular Force8.2.2 Pressure as a Scalar Quantity8.2.3 Incompressible Fluids Under Pressure8.2.4 How Fluids Exert Pressure on Surfaces8.2.5 Absolute, Reference, and Gauge Pressure8.2.6 Pressure in a Vertical Fluid Column8.3 Fluids and Newton’s Laws0/08.3.1 Newton’s Laws and Fluid Motion8.3.2 Internal Interactions and External Forces8.3.3 The Buoyant Force on an Object8.3.4 Particle Model of Buoyancy8.3.5 Archimedes’ Principle and Displaced Fluid8.4 Fluids and Conservation Laws0/08.4.1 Pressure Differences and Fluid Flow8.4.2 Mass Flow In and Out of a Tube8.4.3 Flow Rate, Area, and Speed8.4.4 Continuity Equation for Incompressible Fluids8.4.5 Energy Changes in the Fluid–Earth System8.4.6 Bernoulli’s Equation8.4.7 Torricelli’s Theorem8.4.8 Ideal-Fluid Boundaries and Full Pipes8. FluidsPremium8.1 Internal Structure and Density0/08.1.1 States of Matter and Particle Interactions8.1.2 What Makes a Substance a Fluid?8.1.3 Density as Mass per Unit Volume8.1.4 Ideal Fluids: Incompressible and Nonviscous8.2 Pressure0/08.2.1 Pressure from a Perpendicular Force8.2.2 Pressure as a Scalar Quantity8.2.3 Incompressible Fluids Under Pressure8.2.4 How Fluids Exert Pressure on Surfaces8.2.5 Absolute, Reference, and Gauge Pressure8.2.6 Pressure in a Vertical Fluid Column8.3 Fluids and Newton’s Laws0/08.3.1 Newton’s Laws and Fluid Motion8.3.2 Internal Interactions and External Forces8.3.3 The Buoyant Force on an Object8.3.4 Particle Model of Buoyancy8.3.5 Archimedes’ Principle and Displaced Fluid8.4 Fluids and Conservation Laws0/08.4.1 Pressure Differences and Fluid Flow8.4.2 Mass Flow In and Out of a Tube8.4.3 Flow Rate, Area, and Speed8.4.4 Continuity Equation for Incompressible Fluids8.4.5 Energy Changes in the Fluid–Earth System8.4.6 Bernoulli’s Equation8.4.7 Torricelli’s Theorem8.4.8 Ideal-Fluid Boundaries and Full Pipes