Units of Measurement

  • In the context of forces and motion, units are essential in defining quantities scientifically.
  • The international standard of unit of measurement in Physics is the SI unit.


  • The SI unit of force is the newton (N).


  • The SI unit for mass is the kilogram (kg).


  • Distance is measured in metres (m) and time in seconds (s).

Velocity and Speed

  • Velocity and speed are measured in metres per second (m/s).


  • Acceleration is measured in metres per second squared (m/s²).


  • The unit of momentum is kilogram metre per second (kg m/s).

Gravitational Force

  • Gravitational force is typically measured in newtons (N).


  • Weight is measured in newtons (N), it’s a specific force dependent on gravity.


  • The unit for energy is the joule (J).

Work Done

  • Work done, is the energy transferred when a force acts upon an object to cause a displacement, it is also measured in joules (J).


  • The unit for power is the watt (W).

Remember, understanding units is very important when solving problems related to forces and motion. Incorrect units can often lead to wrong answers. Familiarise yourself with these units so that you can comfortably convert between them when necessary.