The Story of Physics
Follow our guided path to understand the laws of the universe, from the motion of a falling apple to the fabric of spacetime.
Unit I: The Science of Motion (Kinematics)
Our journey begins with the most fundamental question: How do things move? We'll learn to describe motion with precision using concepts like displacement, velocity, and acceleration.
Introduction to Kinematics
Discover the difference between distance and displacement, and speed and velocity. Build your first interactive graph of motion.
Acceleration
What does it mean to "speed up" or "slow down"? Explore the concept of acceleration and its relationship to velocity and time.
Free Fall
Investigate the motion of objects under the influence of gravity alone. Why do all objects fall at the same rate?
Unit II: Forces and Newton's Laws (Dynamics)
We've learned how to describe motion. Now, we'll uncover *why* motion changes. This unit explores the concept of forces and Isaac Newton's three fundamental laws that form the bedrock of all classical mechanics.
Introduction to Forces
What is a force? Explore the difference between contact forces and field forces, and learn to represent them with free-body diagrams.
Newton's Laws of Motion
Interactively discover Newton's three laws. See how inertia, F=ma, and action-reaction pairs govern the motion of everything in the universe.
Friction & Drag
Explore the forces that oppose motion. Learn the difference between static and kinetic friction and how air resistance affects falling objects.
Unit II Quiz
You've learned about the forces that cause and resist motion. Test your knowledge of Newton's Laws, friction, and drag in the Unit II challenge.
Unit III: Work, Energy, and Power
Now that we understand forces, we can explore a new and powerful way to analyze motion: through the lens of energy. This unit introduces the concepts of work, kinetic energy, potential energy, and power.
Work and Kinetic Energy
Learn the physics definition of "work" and its relationship to an object's energy of motion (kinetic energy) through the work-energy theorem.
Potential Energy & Conservation
Explore stored energy (potential energy) and one of the most fundamental principles in all of science: the Law of Conservation of Energy.
Power
What's the difference between doing work and doing work *quickly*? Discover the concept of power, the rate at which energy is transferred.