Physics for Beginners
Physics makes more sense when you can picture what is happening before you reach for a formula, so this free companion page starts with the physical story. Start with motion, build one idea at a time, and use the short lessons and flashcards whenever a chapter feels unfamiliar.
A simple way to use the book
- Read one topic and pause at the worked example.
- Cover the solution and try the same steps on your own.
- Complete the short practice set before moving ahead.
- Return to the lesson links or flashcards below when a word, symbol, or idea needs another explanation.
- After Chapter 26, take Practice Test 1 without notes. Review every explanation before taking Practice Test 2.
The complete 26-chapter path
The chapters are arranged so that later ideas grow out of earlier ones. You do not need a previous physics course. Basic arithmetic and a little algebra are enough to begin.
Foundations and mechanics
- The Physics Toolkit
- Describing Motion
- Acceleration and Free Fall
- Forces and Newton’s Laws
- Gravity, Circular Motion, and Orbits
- Momentum and Collisions
- Work, Energy, and Power
- Rotation, Torque, and Balance
- Matter and Materials
Fluids, heat, and waves
- Machines, Pressure, and Fluids
- Temperature, Gases, and Thermal Expansion
- Heat Transfer, Phase Changes, and Thermodynamics
- Oscillations, Springs, and Pendulums
- Wave Motion
- Sound, Hearing, and Music
Electricity and magnetism
- Electrostatics
- Electric Circuits and Capacitors
- Magnetism
- Electromagnetic Induction and Devices
- Electromagnetic Waves and Communication
Light and modern physics
- Reflection, Refraction, and Color
- Lenses and Optical Instruments
- Interference, Diffraction, and Polarization
- Quantum and Atomic Physics
- Nuclear Physics
- Experiments, Models, and Data
Beginner lesson library
Use these lessons when you want a second explanation or a quick review. Each link opens in a new tab, so you can keep your place here.
- Chapter 1: The Physics Toolkit: Measurement, Units, Vectors, and Graphs
- Chapter 2: Motion: Speed, Velocity, and Acceleration
- Chapter 3: Acceleration and Free Fall
- Chapter 4: Forces and Newton’s Laws
- Chapter 5: Gravity, Circular Motion, and Orbits
- Chapter 6: Momentum, Impulse, and Collisions
- Chapter 7: Work, Energy, and Power
- Chapter 8: Rotation, Torque, and Balance
- Chapter 9: Matter and Materials
- Chapter 10: Machines, Pressure, and Fluids
- Chapter 11: Temperature, Gases, and Thermal Expansion
- Chapter 12: Heat Transfer, Phase Changes, and Thermodynamics
- Chapter 13: Oscillations, Springs, and Pendulums
- Chapter 14: Wave Motion
- Chapter 15: Sound, Hearing, and Music
- Chapter 16: Electrostatics: Charge, Force, Field, and Potential
- Chapter 17: Electric Circuits and Capacitors
- Chapter 18: Magnetism
- Chapter 19: Electromagnetic Induction, Generators, and Transformers
- Chapter 20: Electromagnetic Waves and Communication
- Chapter 21: Reflection, Refraction, and Color
- Chapter 22: Lenses and Optical Instruments
- Chapter 23: Interference, Diffraction, and Polarization
- Chapter 24: Quantum and Atomic Physics
- Chapter 25: Nuclear Physics, Radiation, and Half-Life
- Chapter 26: Physics Experiments, Models, and Data
Physics Flashcards
Try to say the meaning before opening a card. If you miss it, close the card and test yourself again a few minutes later.
Scalar
A quantity with size but no direction. Speed, time, mass, and temperature are scalars.
Vector
A quantity with both size and direction. Velocity, acceleration, force, and momentum are vectors.
Velocity
How quickly position changes, including the direction of motion.
Acceleration
How quickly velocity changes. An object accelerates when it speeds up, slows down, or changes direction.
Inertia
An object’s resistance to a change in its motion. Greater mass means greater inertia.
Net force
The vector sum of all forces acting on an object.
Weight
The gravitational force acting on an object. Weight can change when gravitational field strength changes.
Momentum
Mass multiplied by velocity. If external impulse on a chosen system is negligible, its total momentum stays constant during an interaction.
Work
Energy transferred by a force acting through a displacement. Only the force component along the displacement contributes. A component opposite the displacement does negative work.
Power
The rate at which work is done or energy is transferred.
Torque
The turning effect of a force about an axis or pivot.
Density
Mass per unit volume.
Pressure
Force divided by the area over which the force acts.
Temperature
A measure related to the average kinetic energy of particles in a substance.
Heat
Energy transferred because of a temperature difference.
Frequency
The number of cycles or vibrations per second, measured in hertz.
Wavelength
The distance between matching points on consecutive waves, such as crest to crest.
Resonance
A large response that occurs when a driving frequency is close to a system’s natural frequency.
Electric field
The force per unit positive test charge at a point in space.
Voltage
The change in electric potential energy per unit charge between two points.
Current
The rate at which electric charge passes a point.
Resistance
A measure of how strongly a component opposes electric current.
Electromagnetic induction
The production of an emf when magnetic flux changes.
Reflection
The return of a wave from a boundary. For a light ray, the angle of reflection equals the angle of incidence.
Refraction
A change in a wave’s direction caused by a change in wave speed as it crosses a boundary.
Diffraction
The spreading of waves around edges or through openings.
Photon
A packet of electromagnetic energy.
Isotope
An atom with the same number of protons as other atoms of its element but a different number of neutrons.
Half-life
The time required for half the unstable nuclei in a sample to decay.
Uncertainty
A stated range that shows the reasonable limits of a measurement.
About the practice tests
The book contains two complete 40-question practice tests. Readers also receive ten different online forms. Those online links stay private, so you will find them only in the book’s online-practice section, not on this public page.
If you are starting from scratch, begin with Chapter 1. The units, graphs, and problem-solving habits introduced there appear throughout the rest of the book.