Cheat Sheet

Physics I Workbook For Dummies Cheat Sheet

From Physics I Workbook For Dummies, 2nd Edition

By Steven Holzner

Avoid difficulties when working on physics by knowing the common issues that can cause trouble in physics problems, understanding physical constants, and grasping principal physics equations.

10 Issues to Avoid When Solving Physics Problems

If you get stumped working on physics formulas, take a deep breath, and recheck your work. Go through these common physics-problem issues to make sure you have avoided them:

  • Mixing units

  • Expressing the answer in the wrong units

  • Swapping radians and degrees

  • Getting sines and cosines mixed up

  • Failing to treat vectors as vectors

  • Neglecting latent heat

  • Getting refraction angles wrong

  • Getting the signs wrong in Kirchhoff’s loops

  • Adding resistors incorrectly

  • Getting ray diagrams wrong

9 Physics Constants to Know

Physics constants, like the mass of a proton or speed of light, are physical quantities with fixed numerical values. This list contains the most common physics constants:

  • Avogadro’s Number: NA = 6.022 × 1023 mol–1

  • Boltzmann’s constant: k = 1.380 × 10–23 J/K

  • Coulomb’s constant: k = 8.99 × 109 N–m2/C2

  • Gas constant: R = 8.314 J/(mol–K)

  • Gravitational constant: G = 6.672 × 10–11 N–m2/kg2

  • Speed of light: c = 2.997 × 108 m/s

  • Charge of electron: e = 1.602 × 10–19 C

  • Mass of proton: mp = 1.672 × 10–27 kg

  • Mass of electron: me = 9.109 × 10–31 kg

Important Physics Equations to Remember

Physics is packed with formulas and equations. This comprehensive list, arranged by topic, represents essential physics equations you need to keep handy when you’re dealing with physics formulas.