| Formula
| Alternative
| Unit
|
| pressure = force/area
| Pa or Nm-2
|
| speed = distance/(time taken)
| m s-1
|
|
| Work done = Force distance moved in the direction of the force
| J
|
| Power = energy transformed/(time taken)
| W or Js-1
|
| Electrical energy = Power time
Electrical energy in kWh = Power in kW time in hours
| J or kWh
|
| electrical energy = potential difference current time
| J
|
| -
| moment of a force about a pivot = force perp distance from force to pivot
| Nm
|
| -
| sum of clockwise moments = sum of anticlockwise moments
| Nm
|
| acceleration = change in velocity/change in time
| ms-2
|
| Force = mass acceleration (constant mass)
| N
|
| wave speed = frequency wavelength
| ms-1
|
| Charge = current time (constant current)
| C
|
| potential difference = current resistance
| V
|
| electric power = current potential difference
| W or Js-1
|
| weight = mass gravitational field strength
| N
|
| kinetic energy = ½ mass velocity2
| J
|
| increase in gravitational potential energy = mass g change in height (Dh small enough that g is constant)
| J
|
| momentum = mass velocity
| kg m s-1
|
| centripetal force = mass velocity2/radius
| N
|
| potential difference = energy transformed/charge transferred
| V
|
| Resistance of element = potential difference across element/current
| ohms
|
| resistance = resistivity length/area
| ohms
|
| capacitance = charge/potential difference
| F
|
| Ideal gas law
| J mol-1
|
| electric force (radial)
| N
|
| electric field strength for uniform field
| V m-1
|
| electric field strength for radial field
| V m-1
|
| electric potential at a point
| V
|
| gravitational force
| N
|
| gravitational field strength radial
| N kg-1
|
| gravitational potential at a point
| J kg-1
|
