Equations and Constants

This page contains equations and constants that you may find useful during this course. You are welcome to print a copy of this page and use it during tests but you may not annotate this page in any way if you are going to use it in a test situation - it is your responsibility to understand these equations and their limitations...

Equations

  • vav = (x2 - x1) / (t2 - t1) = Δx / Δt
  • v = dx / dt
  • vav = (r2 - r1) / (t2 - t1) = Δr / Δt
  • v = dr / dt
  • aav = (v2 - v1) / (t2 - t1) = Δv / Δt
  • a = dv / dt

The next 5 equations assume that the acceleration is constant and that motion is linear:

  • a = (v - v0) / t
  • v = v0 + a t
  • Δx = ½ (v + v0) t
  • Δx = v0 t + ½ a t 2
  • v2 = v02 + 2 a Δx


  • Fcent = mv² / r
  • Fnet = ma
  • W = mg
  • fs <= µs n
  • fs max = µs n
  • fk <= µk n
  • µ = tan θ
  • component of weight perpendicular to inclined plane = n = mg sin θ
  • component of weight parallel to inclined plane = mg cos θ
  • p = m v
  • F t = Δp

Constants

g = 9.81 m / s² (you may take g = 10 m / s² unless told otherwise)

Density of water = 1000 kg / m3

Density of air at atmospheric pressure and 20°C = 1.2kg / m3