Skill — Estimate quantities using order-of-magnitude reasoning.
Present in chapters
00·00b·01·05
Linked atoms
114 linked atoms.
00 Physical quantities, estimates, equilibrium
- Worked exercise — Bananas to feed the Italian population
- Worked exercise — How big is a small room in litres
- Worked exercise — A giant car park for all the world’s cars
- Scientific notation and orders of magnitude
- Problem — Hairs on a head
- Problem — The mass of the atmosphere
- Problem — The Adriatic Sea
- Problem — How many hairs does a head have
- Problem — Ranking orders of magnitude
- Problem — Breaths in a lifetime
- Problem — Cooking rice, the Fermi way
- Fermi estimates
00b Experimental method
- Problem — Human stopwatch
- Problem — How many repetitions to confirm a law
- Problem — Fermi estimate, measurements of g
- Problem — Fermi estimate, school experiments in Italy
01 Kinematics
- h
- Problem — Fermi estimate, g on Mars
- Problem — Fermi estimate, reaction time
- Problem — Fermi estimate, speed of a dive
- Estimating g with a marble
02 Forces and Newton’s laws
03 Inclined plane and circular motion
- Centripetal acceleration of Earth’s rotation
- Edge of a CD
- Aircraft carrier catapult
- Skier at limit speed
- Estimating the centripetal force on a passenger
04 Energy and work
- Problem — Efficiency of a wind turbine
- Problem — Estimating the kinetic energy of a car
- Problem — Estimating the energy to climb stairs
- Problem — Fermi estimate, the calories in an apple
- Problem — Fermi estimate, power of a human being
- Problem — Temperature of a car’s brakes
04b Oscillations and simple harmonic motion
- Problem — Natural frequency of a skyscraper
- Problem — Footsteps on a bridge
- Problem — Vibrations of the Sun
05 Momentum and collisions
- Recoil on ice
- Jumping off a bench
- Fermi estimate, kicking a ball
- Fermi estimate, deflecting an asteroid
- Fermi estimate, mass of the projectile
06 Centre of mass
07 Rotational dynamics
- Problem — Angular momentum of Earth’s rotation
- Problem — Earth’s orbital angular momentum
- Problem — Fermi estimate: tyre on the motorway
08 Universal gravitation
- Falling to the centre of the Earth
- Escaping the Solar System
- Gravity at different altitudes on Everest
- The Sun, the Earth and a car — comparing gravitational forces
- Estimating the radius of the geostationary orbit
- Estimating the mass of the Sun
- Estimating the mass of the Galaxy
08b Thermology
09 Kinetic theory of gases
- Worked exercise — Escape of hydrogen from the ionosphere
- Problem — Diffusion of a smell
- Problem — Estimating collisions per second on a hand
- Problem — Estimating collisions on a square centimetre
- Problem — Fermi estimate: molecules in a room
- Problem — Fermi estimate: sauna
- Problem — Fermi estimate: collisions on the skin
10 Irreversible transformations and energy balance
- Fermi estimate: air in a room
- Fermi estimate: ice in a drink
- Estimate: work of a hot air bubble
- Estimate: boiling time
11 Entropy
- Fermi estimate: entropy of a burnt book
- Fermi estimate: S of the Sun vs the Earth
- Fermi estimate: ΔS of the human body
- Estimate: entropy of a cup of coffee
12 Cycles and heat engines
- Problem — Real air conditioner (SEER)
- Problem — Morning shower
- Problem — Power of a coal power plant
- Problem — Estimating the power of an air conditioner
13 Coulomb force and electrostatics
- Problem — Fraction of electrons to transfer
- Problem — Fermi estimate: capacitance of the Earth
- Problem — Fermi estimate: force between two electrons
15 Electric circuits
- Problem — electric boiler
- Problem — capacity of an AA battery
- Problem — energy of a laptop
- Problem — AA battery for an LED torch
16 Waves
- Problem — Maximum distance of thunder
- Problem — Acoustic power of a conversation
- Fermi estimate: lightning and thunder
- Fermi estimate: whistling microphone
17 The magnetic field
- Field of a household cable and a compass
- Force of an MRI on a paperclip
- Turns per metre for 1 mT
- Estimating Earth’s magnetic field
18 Electromagnetic induction
- Problem — Earth’s field and a train window
- Problem — The AM antenna at home
- Estimating the EMF in a loop made by the hand
19 Maxwell’s equations and electromagnetic waves
- Worked exercise — The Sun, Milan-Naples and mass loss
- Problem — WiFi intensity at 10 metres
- Problem — Radiation pressure at ground level
- Problem — Radiation pressure at Earth’s orbit
- Problem — Fermi estimate: FM station
20 Special relativity
- Problem — Energy of a fission bomb
- Problem — Estimating the GPS relativistic correction
- Kinematic delay of GPS clocks
- Fermi estimate, one gram of matter
21 Introduction to quantum mechanics
- Problem — Uncertainty of the electron in an atom
- Problem — Fermi estimate, atoms in an apple
- Problem — Fermi estimate, photons from an LED
- Temperature of the Sun using Wien’s law