User Tools

Site Tools


Sidebar

gcse_forces_massweight

Mass and Weight

  • Mass is how much of you there is. It is measured in kg and is a scalar. It does not change from place to place.
  • Weight is how hard the force of gravity pulls on you. It is measured in N (it is a force!) and is a vector. It does change from place to place.

Why do we have weight?

  • The force of gravity pulls you towards the centre of the Earth.
  • On Earth, the gravitational field strength is 10 N/kg.
  • This means that for every kg of mass you have, 10 N of force is pulling you towards the centre of the Earth…
  • On the Moon the gravitational field strength is only 1.6 N/kg. The same mass has less weight on the moon than it does on Earth.
  • In space there is no gravity. You are weightless!

Factors affecting weight

Your weight is bigger if:

  • You have more mass
  • You are in a stronger gravitational field.

The formula!

  • Weight = mass x gravitational field strength
  • Mass = weight divided by gravitational field strength
  • Gravitational field strength = weight divided by mass
gcse_forces_massweight.txt · Last modified: 2017/11/05 20:41 by rheadi