Physics equations

• kinetic energy


  0.5 × mass × (speed)2
• elastic potential energy


  0.5 × spring constant × (extension)2
• gravitational potential energy


  mass × gravitational field strength × height
• change in thermal energy

  mass × specific heat capacity × temperature change
• power


  energy transferred / time
• power


  work done / time
• efficiency


  useful output energy transfer / total input energy transfer
• efficiency


  useful power output / total power input
• charge flow


  current × time
• potential difference


  current × resistance
• power


  potential difference × current
• power


  (current)2 × resistance
• energy transferred


  power × time
• energy transferred


  charge flow × potential difference
• potential difference across primary coil × current in primary coil

  potential difference across secondary coil × current in secondary coil
• density


  mass / volume
• thermal energy for a change of state

  mass × specific latent heat
• weight


  mass × gravitational field strength
• work done


  force × distance (along the line of action of the force)
• force


  spring constant × extension
• distance travelled


  speed × time
• acceleration


  change in velocity / time taken
• (final velocity)2 - (initial velocity)2

  2 × acceleration × distance
• resultant force


  mass × acceleration
• momentum


  mass × velocity
• period


  1 / frequency
• wave speed


  frequency × wavelength
• force on a conductor (at right angles to a magnetic field) carrying a current


  magnetic flux density × current × length
• Resultant force

  resultant force = weight - drag