equations

• weight (N) =


  mass (kg) x gravitational field strength (N/kg)
• weight equation


  W=mg
• work done (J) =

  force (N) x distance (m)
• work done equation


  W=Fs
• force applied to a spring (N) =

  spring constant (N/m) x extension (m)
• force applied to a spring equation

  F=ke
• moment of a force (Nm) =


  force (N) x distance (m) (normal to direction of the force)
• moment of a force equation

  M=Fd
• pressure (N/m² or Pa) =

  force normal to a surface (N) / area of that surface (m²)
• pressure equation


  p=F/A
• distance (m) =


  speed (m/s) x time (s)
• distance equation


  s=vt
• acceleration (m/s²) =


  change in velocity (m/s) / time taken (s)
• acceleration equation


  Δv/t
• resultant force (N) =

  mass (kg) x acceleration (m/s²)
• resultant force equation


  F=ma
• momentum (kg m/s) =

  mass (kg) x velocity (m/s)
• momentum equation


  p=mv
• kinetic energy (J) =

  0.5 x mass (kg) x speed² (m/s)
• kinetic energy equation


  KE=1/2mv²
• gravitational potential energy (J) =

  mass (kg) x gravitational field strength (N/kg) x height (m)
• gravitational potential energy equation

  GPE=mgh
• power (W) =


  work done (J) / time (s)
• power equation


  P=W/t
• efficiency =


  useful energy output / total energy input
• wave speed (m/s) =

  frequency (Hz) x wavelength (m)
• wave speed equation


  v=fλ
• charge flow (C) =

  current (A) x time (s)
• charge flow equation


  Q=It
• potential difference (V) =

  current (A) x resistance (Ω)
• potential difference equation


  V=IR
• power (W) =


  potential difference (V) x current (A)
• power equation


  P=IV
• power (W) =


  current² (A) x resistance (Ω)
• power equation


  P=I²R
• energy transferred (J) =

  power (W) x time (s)
• energy transferred equation


  E=Pt
• energy transferred (J) =

  charge flow (C) x potential difference (V)
• energy transferred equation


  E=QV
• energy transferred (J) =

  current (A) x voltage (V) x time (s)