4.1 and 4.2

• One kilogram of mass has a force of ten newtons on Earth.
• We measure mass in kilograms and weight in newtons.
• Weight is the amount of force that pulls objects towards the Earth.
• Mass is the amount of matter in an object.
• We use forcemeters to measure weight.
• What is weight?

  Weight is the amount of force that pulls objects towards the Earth.
• Force diagrams show the direction and size of forces.
• Forces act in pairs. Each force in a force pair acts in the opposite direction to the other
• Force act in different directions