College Physics for AP Courses 2e PDF Download – OpenStax (Algebra-Based Physics)

College Physics for AP Courses 2e is OpenStax’s free algebra-based physics textbook, written for the College Board’s AP Physics 1 and AP Physics 2 courses. Its 34 chapters run from kinematics and Newton’s laws through fluids, thermodynamics, waves, electricity and magnetism, optics and modern physics, and every chapter opens with a Connection for AP Courses that maps the content to the AP Big Ideas.

Students outside the AP system can use it too. Pre-university students (FSc, A-Level and similar programs) get a clear English-language text that uses only algebra and trigonometry, and first-year university students, including BSCS students with a non-calculus physics requirement, can use it for revision and practice. One honest note: it is an AP adaptation of OpenStax College Physics, so if you want the standard text without the AP material, look at College Physics 2e on this site instead.

Book Overview

Chapter List

Chapter 1: Introduction: The Nature of Science and Physics

Difficulty: Easy · AP Connection: prepares for Big Ideas 2 and 7 and Science Practices 1–3 · Key topics: scientific method, models and laws, SI units, conversion factors, accuracy and precision, significant figures, order-of-magnitude estimates

Chapter 1 builds the toolkit every later chapter leans on. It starts with what physics studies and how a model, a theory and a law differ, then introduces physical quantities and the four fundamental units — metre, kilogram, second and ampere — together with metric prefixes and unit conversion by conversion factors. The last two sections deal with accuracy, precision and significant figures, and with estimating by orders of magnitude. The chapter’s Connection for AP Courses says it addresses no Big Idea directly; instead it prepares the habits behind the AP science practices, such as using models and using mathematics appropriately.

Key Points:

• Physics deals with energy, matter, space and time and their interactions
• The four fundamental units used in the book are the metre (m), kilogram (kg), second (s) and ampere (A); every other unit is a combination of these
• The metric system relates quantities through powers of 10, using standard prefixes such as kilo-, milli- and micro-
• A unit conversion multiplies by a conversion factor, a ratio that relates equal quantities in different units
• Accuracy is how close a result is to the true value; precision is how reproducible it is, and significant figures show the precision of a measurement
• Percent uncertainty compares the uncertainty of a measurement with its size, which is useful when comparing the quality of two measurements
• Order-of-magnitude approximation lets you check whether an answer is even plausible before you calculate carefully

Memory Tip: Picture darts on a board: tightly grouped darts far from the bullseye are precise but not accurate; scattered darts around the bullseye are accurate on average but not precise.

Common Mistake: Copying every digit from the calculator display. A result cannot have more significant figures than the least precise measurement that went into it.

Important Questions:

• How many significant figures does the measurement 0.00340 m have? Three. The leading zeros only locate the decimal point, while the 3, the 4 and the trailing 0 are significant, so the value is written to the nearest 0.00001 m.
• Which four fundamental units does the book use, and what do they measure? The metre (length), the kilogram (mass), the second (time) and the ampere (electric current). Units such as the newton and the joule are derived by combining them, for example 1 J = 1 kg·m²/s².

Chapters 2–3: Kinematics and Two-Dimensional Kinematics

Difficulty: Easy–Medium · AP Connection: Big Idea 3, Enduring Understanding 3.A (reference frames) · Key topics: displacement, vectors and scalars, velocity, acceleration, constant-acceleration equations, free fall, motion graphs, vector components, projectile motion, relative velocity
Chapters in this block: 2. Kinematics · 3. Two-Dimensional Kinematics

These two chapters describe motion without asking what causes it. Chapter 2 separates distance from displacement and speed from velocity, defines instantaneous and average acceleration, and then develops the constant-acceleration equations, with falling objects as the main example and graphs of position and velocity against time as a second way to read the same motion. Chapter 3 extends this to two dimensions: vectors are added graphically and by components, horizontal and vertical motion are treated as independent, and projectile motion and relative velocity close the chapter. The AP Connection ties both chapters to the idea that an observer in a given reference frame describes motion with position, displacement, velocity and acceleration.

Key Points:

• Displacement is the change in position, Δx = x_f − x₀; it is a vector, while distance traveled is a scalar
• For constant acceleration, v = v₀ + at and x = x₀ + v₀t + ½at² describe the whole motion
• Near Earth’s surface a falling object has a constant downward acceleration, g = 9.80 m/s², when air resistance is ignored
• On a position–time graph the slope is velocity; on a velocity–time graph the slope is acceleration
• The horizontal and vertical components of a vector are independent, which is why a projectile’s horizontal velocity stays constant while its vertical velocity changes at rate g
• Vectors add by the head-to-tail method graphically, or by adding components analytically; relative velocities add as vectors too

Memory Tip: Each kinematic equation leaves out one of the five variables (x, v, v₀, a, t). Find the one variable you neither know nor need, and pick the equation that omits it.

Common Mistake: Mixing up signs. If upward is positive, a falling object’s acceleration is −9.80 m/s²; using +9.80 on the way down gives an impossible answer.

Important Questions:

• A ball is thrown straight up at 20 m/s. How long does it take to return to the thrower’s hand? At the top its velocity is zero, so the rise takes t = v₀/g = 20/9.8 ≈ 2.0 s. The return trip takes the same time, so the total is about 4.1 s.
• A stone is kicked horizontally at 15 m/s from the edge of a 45 m cliff. How long is it in the air and how far from the base does it land? Only the vertical motion sets the time: 45 = ½(9.8)t² gives t ≈ 3.0 s. The horizontal velocity stays 15 m/s, so the stone lands about 15 × 3.0 ≈ 45 m from the cliff.

Chapters 4–5: Dynamics, Friction, Drag and Elasticity

Difficulty: Medium · AP Connection: Big Idea 3 (forces); Chapter 4 also touches Big Idea 5 · Key topics: force and free-body diagrams, Newton’s three laws, weight, normal force, tension, friction, drag, Stokes’ law, Hooke’s law, stress and strain, the four basic forces
Chapters in this block: 4. Dynamics: Force and Newton’s Laws of Motion · 5. Further Applications of Newton’s Laws: Friction, Drag, and Elasticity

Chapter 4 is the book’s dynamics core. It builds the idea of force, states Newton’s three laws, introduces systems and external forces, and works through weight, the normal force and tension before a problem-solving strategy and further applications. A closing extended topic previews the four basic forces. Chapter 5 then applies the laws to real contact forces: static and kinetic friction through coefficients, drag on large and small objects (including Stokes’ law), and elastic deformation described by Hooke’s law, Young’s modulus, stress and strain. Chapter 5’s AP Connection links it to the nature of forces and to using free-body diagrams to find net force.

Key Points:

• Newton’s second law is a = F_net/m, usually written F_net = ma; weight is w = mg
• Newton’s third law: when one body exerts a force on a second, the second exerts an equal and opposite force on the first, and the two forces act on different bodies
• A free-body diagram shows all external forces on one body, and it is the starting point for almost every dynamics problem
• Static friction obeys f_s ≤ μ_sN, while kinetic friction is f_k = μ_kN
• For large objects in air, drag is F_D = ½CρAv²; for small objects in a viscous fluid, Stokes’ law gives F_s = 6πηrv
• Hooke’s law, F = kΔL, describes elastic deformation, and Young’s modulus Y links stress (F/A) to strain (ΔL/L₀)

Practice Tip: Before writing any equation, draw the free-body diagram and label each force with what exerts it (floor, rope, Earth). Then write F = ma separately along each axis.

Common Mistake: Treating a third-law pair as if it cancels. The two forces act on different bodies, so they never appear together on the same free-body diagram.

Important Questions:

• A 10 kg box slides at constant speed across a floor with μ_k = 0.30. What horizontal push is needed? Constant speed means zero net force, so the push equals kinetic friction: f_k = μ_kN = 0.30 × (10 × 9.8) ≈ 29 N.
• Why does a skydiver eventually stop speeding up? Drag grows with speed (proportional to v² for a large object). When drag equals weight the net force is zero, so acceleration is zero and the skydiver falls at a constant terminal velocity.

Chapter 6: Uniform Circular Motion and Gravitation

Difficulty: Medium · AP Connection: Big Idea 1 (gravitational and inertial mass) and Big Idea 2 (gravitational field) · Key topics: radians, angular velocity, centripetal acceleration and force, Coriolis force, universal gravitation, satellites, Kepler’s laws

Chapter 6 starts by describing rotation with the rotation angle in radians and angular velocity, and links angular and linear speed through v = rω. It then shows that circular motion at constant speed still involves acceleration toward the centre, and that a net inward force — the centripetal force — must supply it. A section on fictitious forces and non-inertial frames introduces the Coriolis force. The chapter finishes with Newton’s universal law of gravitation and its use for satellites and Kepler’s laws. Its AP Connection links the chapter to gravitational mass and to the gravitational field of a spherical object.

Key Points:

• The rotation angle is Δθ = Δs/r in radians, where 2π rad = 360° = 1 revolution
• Angular velocity is ω = Δθ/Δt, and linear speed is v = rω
• Centripetal acceleration points toward the centre with magnitude a_c = v²/r = rω²
• Centripetal force is not a new kind of force; it is whichever real force or combination of forces supplies F_c = mv²/r
• Rotating and accelerating frames are non-inertial, so observers there need fictitious forces such as the Coriolis force
• Universal gravitation gives F = Gm₁m₂/r², and Kepler’s third law relates a satellite’s period to the radius of its orbit

Memory Tip: “Centripetal” means center-seeking. It names the direction of the net force, not a separate force to add to your diagram.

Common Mistake: Adding “centripetal force” to the free-body diagram as an extra arrow. Draw only the real forces (tension, gravity, friction, normal force) and say that their inward sum equals mv²/r.

Important Questions:

• A 0.50 kg ball whirls on a 1.0 m string at 4.0 m/s in a horizontal circle. What is the tension? The tension supplies the centripetal force: F = mv²/r = 0.50 × 4.0² / 1.0 = 8.0 N.
• What happens to the gravitational force between two masses if the distance between them is doubled? Gravity follows an inverse-square law, so doubling the distance makes the force one quarter as large.

Chapters 7–8: Work, Energy, Momentum and Collisions

Difficulty: Medium · AP Connection: Big Ideas 3, 4 and 5 (forces, interactions, conservation laws) · Key topics: work, kinetic energy, work-energy theorem, potential energy, conservative forces, power, momentum, impulse, elastic and inelastic collisions, rocket propulsion
Chapters in this block: 7. Work, Energy, and Energy Resources · 8. Linear Momentum and Collisions

Chapter 7 defines work as the transfer of energy by a force acting through a displacement, then develops kinetic energy, the work-energy theorem, gravitational potential energy and the split between conservative and nonconservative forces. It brings them together in conservation of energy, adds power, and closes with human energy use and world energy sources. Chapter 8 introduces linear momentum, impulse, and the conservation of momentum for an isolated system, then treats elastic and inelastic collisions in one dimension, point-mass collisions in two dimensions and rocket propulsion. Together they give two conservation laws for problems where force analysis alone is awkward.

Key Points:

• Work is W = Fd cosθ, measured in joules; it is zero when the force is perpendicular to the displacement
• Kinetic energy is KE = ½mv², and the work-energy theorem says net work equals the change in kinetic energy
• Gravitational potential energy near Earth changes by ΔPE_g = mgh; only differences in potential energy have physical meaning
• Momentum is p = mv, and the net external force equals the rate of change of momentum, F_net = Δp/Δt
• Impulse, Δp = F_netΔt, explains why a longer stopping time means a smaller average force
• Momentum is conserved in an isolated system; kinetic energy is conserved only in elastic collisions

Memory Tip: Force acting over time changes momentum (impulse); force acting over distance changes energy (work). Ask which one the problem gives you.

Common Mistake: Using W = Fd without the cosine of the angle. The normal force and the centripetal force do no work because they are perpendicular to the motion, and friction does negative work.

Important Questions:

• A 1000 kg car moving at 20 m/s brakes to a stop. How much work do the brakes do? By the work-energy theorem, W = ΔKE = 0 − ½(1000)(20)² = −2.0 × 10⁵ J. The negative sign means the brakes remove that energy from the car.
• A 1.0 kg cart moving at 2.0 m/s hits a 3.0 kg cart at rest and the two stick together. What is the final speed, and is kinetic energy conserved? Momentum is conserved: 1.0 × 2.0 = 4.0 × v, so v = 0.50 m/s. Kinetic energy falls from 2.0 J to 0.50 J, so this perfectly inelastic collision loses 1.5 J.

Chapters 9–10: Statics, Torque and Rotational Motion

Difficulty: Medium–Hard · AP Connection: Big Idea 3 (torque), with Chapter 10 also reaching Big Ideas 4 and 5 · Key topics: equilibrium conditions, torque and lever arm, stability, simple machines, muscles and joints, angular acceleration, rotational inertia, rotational kinetic energy, angular momentum, gyroscopes
Chapters in this block: 9. Statics and Torque · 10. Rotational Motion and Angular Momentum

Chapter 9 states the two conditions for equilibrium — zero net force and zero net torque — defines torque as τ = rF sinθ, and applies the conditions to stability, simple machines and the forces and torques inside muscles and joints. Chapter 10 then builds rotational counterparts of linear motion: angular acceleration and the tangential acceleration it produces, rotational kinematics, rotational inertia and net torque, rotational kinetic energy, angular momentum and its conservation, collisions of extended bodies, and the vector side of angular momentum seen in gyroscopes. Both chapters tie to the idea that a force can cause a torque.

Key Points:

• Equilibrium needs two conditions: net force = 0 and net torque = 0
• Torque is τ = rF sinθ = r_⊥F, where r_⊥ is the perpendicular lever arm; counterclockwise torques are positive by convention
• Angular acceleration is α = Δω/Δt, and tangential acceleration is a_t = rα
• The rotational kinematic equations mirror the linear ones, with θ, ω and α replacing x, v and a
• Newton’s second law for rotation is net τ = Iα, where the rotational inertia I depends on how mass is distributed about the axis
• Angular momentum L = Iω is conserved when no net external torque acts on the system

Memory Tip: Rotation mirrors straight-line motion: x → θ, v → ω, a → α, m → I, F → τ, p → L. Learn the linear set once and translate.

Common Mistake: Using the whole force in the torque formula. Only the component perpendicular to the line from the pivot to the point of application produces torque.

Important Questions:

• A 20 kg child sits 1.5 m from the pivot of a seesaw. Where must a 30 kg child sit on the other side to balance it? Balance needs equal torques about the pivot: 20 × 1.5 = 30 × d, so d = 1.0 m.
• Why does a spinning skater speed up when she pulls her arms in? With no net external torque, angular momentum L = Iω is conserved. Pulling the arms in lowers her rotational inertia I, so ω must rise.

Chapters 11–12: Fluid Statics and Fluid Dynamics

Difficulty: Medium · AP Connection: Big Idea 7 (pressure) in Chapter 11 and Big Idea 5 (Bernoulli and continuity) in Chapter 12 · Key topics: density, pressure, pressure with depth, Pascal’s principle, gauge pressure, Archimedes’ principle, surface tension, flow rate, Bernoulli’s equation, viscosity, turbulence, diffusion
Chapters in this block: 11. Fluid Statics · 12. Fluid Dynamics and Its Biological and Medical Applications

Chapter 11 defines a fluid and then builds the statics of fluids: density, pressure, how pressure changes with depth (P = hρg), Pascal’s principle for hydraulic systems, gauge versus absolute pressure, Archimedes’ principle for buoyancy, and surface tension and capillary action, ending with pressures in the human body. Chapter 12 moves to fluids in motion: flow rate and the continuity relation, Bernoulli’s equation and its applications, viscosity and laminar flow with Poiseuille’s law, the onset of turbulence, motion of an object in a viscous fluid, and molecular transport by diffusion and osmosis.

Key Points:

• Density is ρ = m/V and pressure is P = F/A; the SI unit of pressure is the pascal, 1 Pa = 1 N/m²
• Pressure due to a column of liquid is P = hρg, so it depends on depth and density, not on the container’s shape
• Pascal’s principle: a pressure change applied to an enclosed fluid is transmitted undiminished throughout it, which is how hydraulic lifts multiply force
• Archimedes’ principle: the buoyant force equals the weight of the fluid displaced by the object
• Flow rate is Q = V/t, which also equals the cross-sectional area times the average velocity (Q = Av); for an incompressible fluid A₁v₁ = A₂v₂
• Bernoulli’s equation, P + ½ρv² + ρgh = constant, expresses conservation of energy along a streamline of ideal flow

Memory Tip: Squeeze a garden hose: a narrower opening gives faster flow (continuity), and faster flow goes with lower pressure (Bernoulli).

Common Mistake: Confusing gauge pressure with absolute pressure. A tyre gauge reads pressure above atmospheric; add about 1.01 × 10⁵ Pa when a formula needs absolute pressure.

Important Questions:

• What is the gauge pressure at the bottom of a 10 m deep fresh-water pool? P = ρgh = 1000 × 9.8 × 10 ≈ 9.8 × 10⁴ Pa, which is close to one atmosphere.
• Water moves at 2.0 m/s in a pipe that narrows to half its radius. How fast does it move in the narrow part? Area scales with radius squared, so halving the radius cuts the area to one quarter. By continuity the speed rises to 4 × 2.0 = 8.0 m/s.

Chapters 13–15: Temperature, Heat and Thermodynamics

Difficulty: Medium · AP Connection: Big Ideas 4, 5 and 7 (energy transfer, conservation, probability) · Key topics: temperature scales, thermal expansion, ideal gas law, kinetic theory, specific heat, latent heat, conduction, convection, radiation, first and second laws, heat engines, entropy
Chapters in this block: 13. Temperature, Kinetic Theory, and the Gas Laws · 14. Heat and Heat Transfer Methods · 15. Thermodynamics

Chapter 13 starts from temperature scales and the zeroth law, covers thermal expansion, the ideal gas law and the kinetic-theory explanation of pressure and temperature, and ends with phase changes and humidity. Chapter 14 separates heat from work, then uses Q = mcΔT and latent heat for calculations and surveys conduction, convection and radiation. Chapter 15 states the first law of thermodynamics (ΔE_int = Q − W), analyses isobaric, isochoric, isothermal and adiabatic processes, and introduces heat engines, Carnot efficiency, heat pumps and refrigerators, entropy and its statistical interpretation. The AP Connection treats the second law and entropy qualitatively.

Key Points:

• Kelvin temperature is T_K = T_C + 273.15; absolute zero is the temperature with no molecular motion
• The ideal gas law relates pressure, volume and temperature: PV = nRT (or PV = NkT in terms of molecules)
• Heat is energy transferred because of a temperature difference; the mechanical equivalent is 1.00 kcal = 4186 J
• Temperature change needs Q = mcΔT, and a phase change at fixed temperature needs Q = mL
• The first law is ΔE_int = Q − W: internal energy changes by net heat added minus net work done by the system
• No heat engine can be 100 percent efficient; a Carnot engine sets the upper limit, Eff_C = 1 − T_c/T_h, with temperatures in kelvin

Memory Tip: Objects do not “contain” heat. They have internal energy and a temperature; heat is only the name for energy in transit because of a temperature difference.

Common Mistake: Using Celsius temperatures in the gas law or in Carnot efficiency. These formulas need absolute temperature in kelvin.

Important Questions:

• How much heat is needed to warm 2.0 kg of water from 20°C to 70°C? (c = 4186 J/kg·°C) Q = mcΔT = 2.0 × 4186 × 50 ≈ 4.2 × 10⁵ J.
• What is the maximum efficiency of a heat engine working between 500 K and 300 K? The Carnot limit is 1 − 300/500 = 0.40, so no engine between those temperatures can exceed 40 percent.

Chapters 16–17: Oscillations, Waves and the Physics of Hearing

Difficulty: Medium · AP Connection: Big Idea 6 (waves), with Chapter 16 also linking to Big Ideas 1, 2 and 3 · Key topics: Hooke’s law, period and frequency, simple harmonic motion, pendulum, resonance, wave superposition, sound speed, intensity and decibels, Doppler effect, standing waves, ultrasound
Chapters in this block: 16. Oscillatory Motion and Waves · 17. Physics of Hearing

Chapter 16 starts from Hooke’s law and elastic potential energy, defines period and frequency, and develops simple harmonic motion, the simple pendulum and the exchange between kinetic and potential energy. It relates uniform circular motion to SHM, then covers damped and forced oscillations with resonance, before turning to waves, superposition, interference and wave intensity. Chapter 17 applies the wave ideas to sound: speed of sound, frequency and wavelength, intensity and the decibel scale, the Doppler effect and sonic booms, standing waves in air columns, the physics of the ear, and ultrasound.

Key Points:

• Simple harmonic motion arises when the restoring force follows Hooke’s law, F = −kx; the period of a mass on a spring is T = 2π√(m/k)
• Period and frequency are inverses, f = 1/T, and for a simple pendulum at small angles T = 2π√(L/g)
• In SHM the total mechanical energy stays constant while it shifts between kinetic and elastic potential energy
• Resonance occurs when a driving force matches a system’s natural frequency, producing a large amplitude
• For any wave, v = fλ; the speed of sound in air depends on temperature, about 331 m/s at 0°C
• Sound intensity level is β = 10 log₁₀(I/I₀) in decibels, with I₀ = 10⁻¹² W/m²

Practice Tip: Simulate a spring or a pendulum (the book links to PhET simulations) and change mass, spring constant and length one at a time. Watch which of them actually changes the period.

Common Mistake: Believing a pendulum’s period depends on its mass or on how far it swings. For small angles only the length and g matter.

Important Questions:

• A 0.50 kg mass hangs on a spring with k = 200 N/m. What is its period of oscillation? T = 2π√(m/k) = 2π√(0.50/200) = 2π × 0.050 ≈ 0.31 s.
• If a sound’s intensity increases by a factor of 10, how many decibels louder is it? β = 10 log₁₀(10) = 10, so the sound level rises by 10 dB.

Chapters 18–21: Electric Charge, Potential, Current and DC Circuits

Difficulty: Medium–Hard · AP Connection: Big Ideas 1, 2, 4 and 5 (charge, fields, conservation laws; Kirchhoff’s rules) · Key topics: conservation of charge, Coulomb’s law, electric field, potential difference, capacitors, current, Ohm’s law, resistivity, power, series and parallel circuits, Kirchhoff’s rules, RC circuits
Chapters in this block: 18. Electric Charge and Electric Field · 19. Electric Potential and Electric Field · 20. Electric Current, Resistance, and Ohm’s Law · 21. Circuits and DC Instruments

Chapter 18 introduces charge and its conservation, conductors and insulators, Coulomb’s law, the electric field and field-line pictures, and ends with electric forces in biology and applications of electrostatics. Chapter 19 turns to electric potential energy and potential difference, potential in a uniform field and around a point charge, equipotential lines, and capacitors with dielectrics, in series and parallel, and the energy they store. Chapter 20 defines current, drift velocity, Ohm’s law, resistance and resistivity, electric power, AC versus DC, and electric hazards. Chapter 21 analyses series and parallel circuits, emf and terminal voltage, Kirchhoff’s rules, DC meters and RC circuits.

Key Points:

• Charge is conserved, and the elementary charge is |q_e| = 1.60 × 10⁻¹⁹ C; like charges repel and unlike charges attract
• Coulomb’s law gives F = kq₁q₂/r², and the electric field is the force per unit charge, E = F/q
• Potential difference is ΔV = ΔPE/q; in a uniform field V = Ed, and 1 eV = 1.60 × 10⁻¹⁹ J
• Current is I = ΔQ/Δt, and Ohm’s law is I = V/R; electric power is P = IV = I²R
• Resistors in series add, R_s = R₁ + R₂ + …, while in parallel 1/R_p = 1/R₁ + 1/R₂ + …
• Kirchhoff’s loop rule expresses conservation of energy and the junction rule expresses conservation of charge

Memory Tip: Series: same current, voltages add. Parallel: same voltage, currents add. The total resistance of a parallel group is always smaller than its smallest branch.

Common Mistake: Adding parallel resistances directly. If your total for a parallel combination is larger than any single resistor, the formula was used wrongly.

Important Questions:

• What happens to the electric force between two point charges if the distance between them is tripled? Coulomb’s law is an inverse-square law, so tripling the distance reduces the force to one ninth.
• A 12 V battery is connected across a 4.0 Ω and a 12 Ω resistor in parallel. What total current does it supply? The equivalent resistance is (4 × 12)/(4 + 12) = 3.0 Ω, so I = V/R = 12/3.0 = 4.0 A.

Chapters 22–24: Magnetism, Induction and Electromagnetic Waves

Difficulty: Hard · AP Connection: Big Idea 4 (electric and magnetic properties of systems) in Chapters 22–23 · Key topics: magnetic poles, ferromagnets, force on a moving charge, Hall effect, Ampere’s law, magnetic flux, Faraday’s and Lenz’s laws, generators, transformers, inductance, RLC circuits, Maxwell’s equations, electromagnetic spectrum
Chapters in this block: 22. Magnetism · 23. Electromagnetic Induction, AC Circuits, and Electrical Technologies · 24. Electromagnetic Waves

Chapter 22 covers magnets and magnetic fields, ferromagnetism and electromagnets, the force on a moving charge and on a current-carrying wire, the Hall effect, torque on a current loop in motors and meters, and the fields produced by currents through Ampere’s law. Chapter 23 introduces magnetic flux and Faraday’s law with Lenz’s law, motional emf, eddy currents, generators, back emf and transformers, then inductance, RL circuits, reactance and RLC series AC circuits. Chapter 24 shows how Maxwell’s equations predict electromagnetic waves, how oscillating charges produce them, how they are organised in the spectrum, and how much energy they carry.

Key Points:

• Magnetic poles always come in north–south pairs; all magnetism is created by electric current, including the atomic currents in ferromagnets
• The magnetic force on a moving charge is F = qvB sinθ, and on a straight current-carrying wire it is F = IlB sinθ
• Magnetic flux is Φ = BA cosθ; Faraday’s law gives emf = −NΔΦ/Δt, and the minus sign is Lenz’s law
• A conductor of length l moving at speed v perpendicular to a field B has a motional emf of Blv
• A transformer changes voltage in proportion to its turns, V_s/V_p = N_s/N_p, which is why power is transmitted at high voltage
• Electromagnetic waves travel at c = 1/√(μ₀ε₀) and range from radio waves to gamma rays; they are produced by accelerating charges

Memory Tip: Nature resists change: the induced current always flows in the direction that opposes the change in magnetic flux that caused it.

Common Mistake: Reading Lenz’s law as “the induced field opposes the original field.” It opposes the change in flux. If the flux is decreasing, the induced field points the same way as the original one.

Important Questions:

• A transformer has 100 turns on the primary and 500 on the secondary. What is the secondary voltage when the primary is 120 V? V_s = V_p(N_s/N_p) = 120 × 5 = 600 V. This is a step-up transformer, so the secondary current is correspondingly smaller.
• A 0.50 m rod moves at 4.0 m/s perpendicular to a 0.20 T magnetic field. What emf is induced between its ends? emf = Blv = 0.20 × 0.50 × 4.0 = 0.40 V.

Chapters 25–27: Geometric Optics, Vision and Wave Optics

Difficulty: Medium · AP Connection: Big Idea 6 (waves and the models of light) · Key topics: reflection, refraction, Snell’s law, total internal reflection, lenses and mirrors, the eye, vision correction, microscopes and telescopes, interference, diffraction, polarization
Chapters in this block: 25. Geometric Optics · 26. Vision and Optical Instruments · 27. Wave Optics

Chapter 25 treats light as rays: the law of reflection, refraction and Snell’s law, total internal reflection, dispersion, and image formation by lenses and mirrors. Chapter 26 applies those ideas to the eye, vision correction for nearsightedness and farsightedness, color vision, microscopes, telescopes and aberrations. Chapter 27 switches to the wave model: interference, Huygens’s principle and diffraction, Young’s double-slit experiment, multiple-slit and single-slit diffraction, the Rayleigh criterion for resolution, thin-film interference and polarization. The AP Connection stresses that different models of light fit different scales.

Key Points:

• The law of reflection says the angle of reflection equals the angle of incidence, both measured from the normal
• The index of refraction is n = c/v, and Snell’s law is n₁ sinθ₁ = n₂ sinθ₂
• Thin lenses and mirrors obey 1/d_o + 1/d_i = 1/f, and magnification is m = −d_i/d_o
• The eye forms a real image on the retina by changing its focal length; myopia is corrected with a diverging lens and hyperopia with a converging lens
• Visible light spans about 380 to 760 nm, and its wavelength in a medium is λ/n while its frequency is unchanged
• Interference and diffraction need the wave model; a double slit gives bright fringes where the path difference is a whole number of wavelengths

Memory Tip: Entering a slower medium (higher n), light bends toward the normal; entering a faster medium, it bends away from the normal.

Common Mistake: Measuring angles from the surface instead of from the normal. Reflection and refraction angles are always measured from the perpendicular line.

Important Questions:

• Light travels from air (n = 1.00) into glass (n = 1.50) at 30° to the normal. What is the angle of refraction? sinθ₂ = (1.00 sin 30°)/1.50 = 0.333, so θ₂ ≈ 19.5°, bent toward the normal.
• In a double-slit experiment, how does the fringe spacing change if red light replaces blue light? Fringe spacing grows with wavelength. Red light has a longer wavelength than blue, so the bright fringes are spaced farther apart.

Chapters 28–29: Special Relativity and Quantum Physics

Difficulty: Medium–Hard · AP Connection: Big Ideas 1 and 5 (properties of systems, conservation laws) · Key topics: Einstein’s postulates, time dilation, length contraction, relativistic momentum and energy, E = mc², blackbody radiation, photoelectric effect, photon momentum, wave-particle duality, uncertainty principle
Chapters in this block: 28. Special Relativity · 29. Quantum Physics

Chapter 28 starts from Einstein’s two postulates and the Michelson–Morley result, then derives simultaneity and time dilation, length contraction, the relativistic addition of velocities, relativistic momentum and relativistic energy, including rest energy E₀ = mc². Chapter 29 begins with the quantization of energy seen in blackbody radiation and atomic spectra, then covers the photoelectric effect, photon energies across the electromagnetic spectrum, photon momentum, the particle-wave duality, the wave nature of matter and the Heisenberg uncertainty principle. Both chapters show where classical mechanics stops being enough.

Key Points:

• Einstein’s postulates: the laws of physics are the same in all inertial frames, and the speed of light c is the same for all observers
• Time dilation is Δt = γΔt₀, with γ = 1/√(1 − v²/c²), and moving objects are contracted along their direction of motion
• Total relativistic energy is E = γmc², so mass and energy are interchangeable; rest energy is E₀ = mc²
• Planck found that oscillator energies come in steps of ΔE = hf, where h = 6.626 × 10⁻³⁴ J·s
• In the photoelectric effect, light of frequency f ejects electrons only if the photon energy hf exceeds the material’s binding energy
• Photons have momentum p = h/λ, matter has a wavelength λ = h/p, and the Heisenberg uncertainty principle limits how well position and momentum can be known together

Memory Tip: Relativity effects scale with γ. At everyday speeds γ is essentially 1, so classical physics works; the effects only become visible near the speed of light.

Common Mistake: Thinking that time dilation is an illusion of the instruments. It is a real difference in elapsed time between frames, confirmed by experiments such as muon lifetimes and atomic clocks on aircraft.

Important Questions:

• A clock on a spaceship moving at 0.80c ticks off 6.0 s. How long does that interval last for an Earth observer? γ = 1/√(1 − 0.64) = 1/0.60 ≈ 1.67, so Δt = γΔt₀ = 1.67 × 6.0 = 10 s.
• What is the energy in electron volts of a photon of 500 nm green light? E = hc/λ ≈ 1240 eV·nm / 500 nm ≈ 2.5 eV.

Chapters 30–31: Atomic Physics and Nuclear Physics

Difficulty: Medium · AP Connection: Big Ideas 1, 3 and 5 (internal structure, strong force, conservation laws) · Key topics: discovery of the atom and electron, Bohr model, X rays, quantum numbers, Pauli exclusion principle, radioactive decay, half-life, binding energy, tunneling
Chapters in this block: 30. Atomic Physics · 31. Radioactivity and Nuclear Physics

Chapter 30 traces how atoms and their parts were discovered, from Brownian motion to the cathode-ray experiments and the nucleus, then presents Bohr’s theory of hydrogen, atomic origins and uses of X rays, excitation and de-excitation applications, matter waves as the cause of quantization, spectral patterns, quantum numbers and the Pauli exclusion principle. Chapter 31 turns to the nucleus: radioactivity and ionizing radiation, radiation detectors, nucleons and nuclear substructure, decay and conservation laws, half-life and activity, binding energy, and quantum tunneling.

Key Points:

• Atoms contain negative electrons and a positive nucleus; the electron’s charge-to-mass ratio is about −1.76 × 10¹¹ C/kg
• Bohr’s model of hydrogen explains discrete spectral lines: a photon is emitted when an electron drops between allowed energy levels
• Quantum numbers label the allowed states of an atom, and the Pauli exclusion principle says no two electrons can share the same set
• Alpha, beta and gamma radiation are ionizing; the range of radiation in matter depends on its charge and energy
• Nuclei are made of protons and neutrons (nucleons), and nuclear decay obeys conservation of charge, nucleon number and energy
• Half-life is the time for half the nuclei in a sample to decay, and binding energy accounts for the mass difference of a nucleus

Memory Tip: After n half-lives, the fraction left is (½)ⁿ: 1/2, 1/4, 1/8, 1/16 … Count half-lives first, then halve that many times.

Common Mistake: Thinking a sample is completely gone after two half-lives. Half remains after one, a quarter after two, and the amount only approaches zero.

Important Questions:

• A radioactive sample has a half-life of 8.0 days. What fraction remains after 24 days? 24 days is three half-lives, so the fraction left is (½)³ = 1/8.
• Why does hydrogen emit light only at certain wavelengths? Its electron can occupy only certain energy levels. When it drops to a lower level it emits a photon whose energy equals the difference between the two levels, so only particular frequencies appear.

Chapters 32–34: Medical Physics, Particle Physics and Frontiers

Difficulty: Easy–Medium · AP Connection: Big Ideas 4 and 5 in Chapters 32–33; Chapter 34 lists none and uses the Big Ideas as a framework · Key topics: medical imaging, radiation dose, fusion and fission, four basic forces, Feynman diagrams, accelerators, quarks, cosmology, dark matter, superconductors
Chapters in this block: 32. Medical Applications of Nuclear Physics · 33. Particle Physics · 34. Frontiers of Physics

Chapter 32 shows nuclear physics in practice: radiopharmaceuticals, SPECT and PET imaging, the biological effects and units of ionizing radiation, therapeutic uses, food irradiation, fusion, fission and nuclear weapons. Chapter 33 moves to elementary particles: virtual particle exchange, the four basic forces and Feynman diagrams, accelerators that create matter from energy, conservation laws and particle patterns, quarks, and grand unified theories. Chapter 34 looks at open questions: cosmology and the Big Bang, general relativity and quantum gravity, superstrings, dark matter, complexity and chaos, and high-temperature superconductors. These chapters are descriptive rather than calculation-heavy.

Key Points:

• Medical imaging uses radiopharmaceuticals; SPECT detects gamma emitters, while PET detects the two annihilation gamma rays from positron emitters
• Radiation dose is measured in rad (1 rad = 0.01 J/kg) or in the SI unit gray (Gy), which measures energy deposited per kilogram of tissue
• Fusion joins light nuclei and fission splits heavy ones; both release energy because the products are more tightly bound
• The four basic forces (gravitational, electromagnetic, weak and strong) act through exchange of carrier particles, shown on Feynman diagrams
• Cosmological red shift (v = H₀d) and the cosmic microwave background both support the Big Bang model
• Dark matter, the unification of forces and quantum gravity are presented as open questions, not settled results

Memory Tip: Fission = split (big nuclei break apart); fusion = fuse (small nuclei join). Energy comes out of both because the products have a higher binding energy per nucleon.

Common Mistake: Confusing radiation with radioactivity. Radioactivity is the decay of unstable nuclei; ionizing radiation is what that decay emits, and its biological effect depends on dose.

Important Questions:

• What is the difference between nuclear fission and nuclear fusion? Fission splits a heavy nucleus such as uranium into lighter ones, while fusion joins light nuclei such as hydrogen isotopes into a heavier one. Both release energy because the products are more tightly bound.
• Name the four basic forces and the particles that carry three of them. Gravitational, electromagnetic, weak nuclear and strong nuclear. The photon carries the electromagnetic force, W and Z bosons carry the weak force, and gluons carry the strong force; the graviton for gravity is still hypothetical.

Download College Physics for AP Courses 2e PDF (Free)

This book is free from its official publisher, OpenStax. The button below opens the official OpenStax book page, where you can download the complete PDF or read the full web edition online.

How to Study This Book

This page groups the book’s 34 chapters into 15 topic blocks that follow the way physics is usually taught, and every block names its real chapter numbers and titles. Nothing in the book is merged or left out; the grouping only keeps a long book readable.

Start every chapter with its Connection for AP Courses. The Preface explains that each chapter opens with this introduction to show which Big Ideas, enduring understandings and essential knowledge the chapter supports, so you can separate what the AP exam needs from interesting extras. Sections marked as Extended Topics, such as 4.8 on the four basic forces and 27.9 on microscopy enhanced by the wave characteristics of light, are examples of the extras.

The Preface says AP Physics 1 covers mechanics, mechanical waves, sound and electrostatics, while AP Physics 2 covers thermodynamics, fluid statics, dynamics, electromagnetism, geometric and physical optics, and quantum, atomic and nuclear physics. Mapped onto this book, Chapters 1–10 and 16–18 are Physics 1 territory, and Chapters 11–15, 19 and 22–31 line up with Physics 2. Chapter 20’s AP Connection says DC circuits are introduced in Physics 1 and developed further in Physics 2, so Chapters 20–21 serve both. Chapters 32–34 are largely applications and open questions, so read their AP Connection to see what is examined. Check the current College Board course description for your exam year, because the book follows the framework as it stood when it was published.

If you are not taking AP, treat the book as a two-semester algebra-based course: Topic Blocks 1–9 (Chapters 1–17) fit a first semester, and Topic Blocks 10–15 (Chapters 18–34) fit a second. Confirm the split against your own syllabus, because courses divide the material differently.

Work the problems in layers. Do the Conceptual Questions first, then the Problems & Exercises, and finish each chapter with the Test Prep for AP Courses, which uses multiple-choice and free-response style items modelled on the exam. Chapters 1 and 34 have no Test Prep section. Read the worked examples closely: each one states a strategy before the solution and ends with a discussion, and the Misconception Alerts address common wrong ideas directly.

Respect the dependencies. Vectors in Chapters 2–3 come before Newton’s laws in Chapter 4, and Newton’s laws plus the energy and momentum chapters (7–8) are assumed in almost every later chapter. Chapter 16 (oscillations and waves) should come before Chapter 17 on sound and before the wave optics of Chapter 27, and the circuit chapters (19–21) are cumulative.

Know what the book does not do. It uses no calculus, so it will not carry you into calculus-based physics, and it does not follow the Punjab Textbook Board syllabus order, so use your board textbook for the exam syllabus and this book for extra conceptual practice. The Appendices (atomic masses, selected radioactive isotopes, useful information, and symbols and notation) and the chapter-by-chapter Answer Key at the back are worth bookmarking.

Used In These Programs

This book is used for algebra-based introductory physics in pre-university and first-year university programs, including BS Computer Science. Browse all General Physics books or all Physics books.

Who Should Read This

College Physics for AP Courses 2e is written for students who need a rigorous but introductory, algebra-based physics course. That includes AP Physics 1 and 2 students, A-Level and FSc students who want a second explanation of a topic in English, and first-year university students whose degree, such as BSCS, includes a non-calculus physics course. It is a poor fit if your course demands calculus-based physics, as engineering and BS Physics courses often do; for those, plan on a calculus-based text such as OpenStax’s University Physics series, and see Calculus Volume 1 for the mathematics. If you are studying for the FSc exams, your Punjab Board book (for example Physics First Year for FSc) defines the exam syllabus, and this book works as extra explanation and practice rather than a replacement.

Applicable Universities

This book is useful for students at Pakistani universities offering BSCS and other programs with a non-calculus physics course, as well as pre-university students, including Punjab University, Virtual University, COMSATS, FAST, UET, NUST, and other HEC-recognized institutions.

FAQs

Related Books

• Physics First Year (Class 11) for FSc – Punjab Board (the local syllabus; different order and depth from this book)
• Physics 2nd Year for FSc – Punjab Board
• Calculus Volume 1 – Strang & Herman (OpenStax), for students heading toward calculus-based physics

For an algebra-based physics course with the AP framework built in, this free OpenStax text covers the full range from kinematics to particle physics. Browse more Physics books or Mathematics books for the rest of your semester.

College Physics for AP Courses 2e, by Irina Lyublinskaya, Gregg Wolfe, Douglas Ingram, Liza Pujji, Sudhi Oberoi, Nathan Czuba, Julie Kretchman, John Stoke, David Anderson, Erika Gasper, Kenneth Podolak and Henry Smith. OpenStax, Rice University. Free under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 licence (CC BY-NC-SA 4.0). Access for free at https://openstax.org/details/books/college-physics-ap-courses-2e