Physics
Build intuition for motion, forces, energy, electricity, optics, and modern physics through first-principles reasoning.
01
Units and MeasurementMeasurement is the foundation of physics.
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02Motion in a Straight LineMotion is everywhere—a falling apple, a speeding car, a spinning electron. Yet describing motion precisely is surprisingly subtle.
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03Motion in a PlaneThe real world isn't one-dimensional.
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04Laws of MotionFor 2000 years, philosophers believed Aristotle: an object moves only if something pushes it, and it stops when the push ends.
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05Work, Energy and PowerForces cause changes in motion, but analyzing motion using forces alone is laborious.
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06System of Particles and Rotational MotionMost objects aren't point particles—they have size and shape. A spinning top, a rolling wheel, a tumbling asteroid—these rotate as well as translate.
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07GravitationGravity shapes the cosmos. It holds planets in orbit, keeps our feet on the ground, and governs the life and death of stars.
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08Mechanical Properties of SolidsSolids are rigid—they resist being pushed, pulled, twisted, or stretched. Yet no material is perfectly rigid.
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09Mechanical Properties of FluidsFluids—liquids and gases—flow and deform easily, fundamentally different from rigid solids. Yet physics governs their behavior just as rigorously.
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10Thermal Properties of MatterHeat and temperature govern the behavior of matter. A frozen nail is brittle; when heated, it becomes malleable.
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11ThermodynamicsThermodynamics governs all energy transformations involving heat.
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12Kinetic TheoryMatter is made of invisible atoms and molecules in constant motion.
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13OscillationsMotion repeats: a pendulum swings back and forth, a mass on a spring bounces up and down, a guitar string vibrates.
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14WavesA pebble dropped in water creates ripples that spread outward.
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