Physics I

Mechanics, Matter, Heat and Waves in 14 chapters — from “Units and Measurement: What a Number Has to Carry” to “Waves”.

Chapters

  1. Units and Measurement: What a Number Has to Carry
    • A number without a unit says nothing
    • Seven units, and why they are defined by constants
    • Units are algebra, so carry them through
    • How many digits have you earned?
    • Arithmetic that does not invent precision
    • Putting a size on your own uncertainty
    • What is left of a quantity when you strip its size away
    • The test every equation must pass
    • Why the bob's mass cannot be in the answer
    • Answering questions nobody gave you data for
  2. Motion in a Straight Line
    • Pinning a moving object to a single number
    • How far it went, and how far it got
    • Squeezing the interval until one instant is left
    • Speed at an instant needs no separate rule
    • When the velocity will not hold still
    • A minus sign is not the same as slowing down
    • Why an area on a graph comes out in metres
    • Three equations, and the one condition they all need
    • What a falling body does, second by second
    • Reaction, braking, and the metres between them
    • Motion depends on who is watching
  3. Motion in a Plane
    • A sign can only point two ways
    • Where you are, and how far you have got
    • Arrows add head to tail
    • Every arrow is two numbers
    • Two ways to multiply, and what each one measures
    • When the path bends, velocity and acceleration part company
    • Velocity is always measured against something
    • One motion in a plane is two motions on a clock
    • What a thrown ball is really doing
    • Turning without speeding up
  4. The Laws of Motion
    • Nothing pushed you
    • The observers the laws are written for
    • Force is the rate at which momentum changes
    • Three equations at once, and no memory of a moment ago
    • Every force has a partner, and it acts somewhere else
    • Drawing only what touches the body
    • What a surface, a string and a spring can push with
    • Friction is an unknown you solve for, not a formula you apply
    • Which way friction points, and what happens when it lets go
    • What holds a car on a bend
  5. Work, Energy and Power
    • What a push has to show for itself
    • Whose work, on what, over what distance
    • Motion as work already banked
    • Adding up a force that will not sit still
    • The theorem survives a force that changes
    • Forces that give the energy back
    • The sum that stays put
    • A spring is that area you can feel
    • When friction is in the room
    • How fast the energy moves
    • What survives a collision
  6. Systems of Particles and Rotational Motion
    • Why a rolling drum is not a sliding block
    • The one point that moves as if it were a particle
    • Why an explosion cannot shift the centre of mass
    • The vector that points along the axis, where nothing is moving
    • Turning at a steady rate
    • Torque, and the point you measure it about
    • What it takes for a body to stay put
    • Moment of inertia, worked out rather than looked up
    • Newton's second law, rewritten for turning
    • Angular momentum, and the two conditions it needs
    • Rolling, where the two motions are locked together
  7. Gravitation
    • A timetable nobody could explain
    • One of Kepler's three laws is not about gravity at all
    • The Moon falls too
    • From points to planets
    • Measuring the constant, and weighing the Earth
    • Gravity is strongest where you are standing
    • The energy stored in being apart
    • What it takes to stay in orbit
    • The energy ledger of a closed orbit
    • The speed that does not come back
  8. Mechanical Properties of Solids
    • A rope, a rail and a mountain
    • Stress is what the solid does back
    • Pull a wire until it breaks, and watch what it does
    • The slope of the straight part is the material
    • Two wires in a row, and a bone under a circus
    • Sliding one face past another, and which face carries the area
    • Squeezed from every side at once
    • Where the work you did on the wire went
    • Sizing a rope, shaping a rail, capping a mountain
  9. Mechanical Properties of Fluids
    • A fluid cannot be pushed sideways
    • Depth, and nothing else, sets the pressure
    • Reading a pressure as a height
    • The upthrust hidden in the depth law
    • One pressure, two pistons
    • What stays the same when a fluid flows
    • Where the pipe narrows, the pressure falls
    • The shear a fluid resists only while it is moving
    • Falling through treacle
    • A liquid surface costs energy
    • Where the liquid meets the solid
  10. Thermal Properties of Matter
    • What flows when a tumbler feels cold
    • Putting a number on hotness
    • Warm it and it grows; stop it and it pushes
    • Where the coefficient will not stay still
    • How much heat a kilogram needs, and how to weigh it
    • The temperature that refuses to rise
    • Pressure decides which state you get
    • Heat crawling through matter
    • Heat carried by the fluid itself
    • Heat that crosses empty space
    • How fast a hot thing cools
  11. Thermodynamics
    • The heat that goes into the river
    • What a wall decides
    • Two numbers fix a gas, and sometimes nothing fixes it
    • Two ways in, and only two
    • The first law, and the sign that decides every answer
    • Why one gas needs two specific heats
    • Work is the area under the path you took
    • The curve that falls faster
    • What grades an engine, and what grades a refrigerator
    • The law that decides which way
    • The best engine that can exist
  12. Kinetic Theory
    • The gas is not sitting still
    • Three lengths, and why they must not be confused
    • One constant that every gas agrees on
    • Pressure is a rain of collisions
    • What a thermometer is really measuring
    • Why squeezing a gas warms it
    • Counting the ways a molecule can hold energy
    • From a mode count to the heat a substance swallows
    • How far a molecule gets before it is hit
  13. Oscillations
    • The motions that come back
    • Which functions of time repeat, and after how long
    • The one oscillation that is a cosine
    • The circle hidden in the to and fro
    • Phase, or where in the cycle you are
    • How fast, and how hard: velocity and acceleration
    • What has to be true of the force
    • Energy passed back and forth
    • The pendulum, resolved along the arc
    • Why every real oscillation dies away
    • Pushing it, and what happens when you push in time
  14. Waves
    • A line of oscillators, tied together
    • One wave, two graphs
    • The pattern moves faster than the string does
    • Tension pulls, mass resists, and the speed is the ratio
    • Sound is a pressure wave, and the pressure is not isothermal
    • Two waves in one place add, then walk away unchanged
    • What a wall does to a pulse
    • The wave that goes nowhere
    • The ends choose the notes
    • What the ear hears when two frequencies arrive together
    • One plucked string, and the whole book behind it