Weight, Mass and Gravity

• Gravity attracts all masses, this has 2 important effects:
  1. on the surface of a planet, it makes all things acceletate towards the ground (same acceleration- approximately 10 m/s2 on Earth)
  2. It gives everything a weight (N)

• the amount of stuff in an object
• for any given object, it will have the same value anywhere in the universe
• measured in Kg (kilograms)
• measured with a mass balance

• caused by the pull of gravitational force
• weight changes value in different parts of the universe
• measured in N (Newtons)
• measured using a spring balance or a newton meter

Weight (N) = Mass (Kg) x Gravitational Field Srength (10 N/Kg on Earth)

• Example question:
  What is the weight, in newtons, of a 10Kg mass on Earth? 

Weight = 10 x 10 = 100 N