weight, mass and gravity

• gravitational force is the force of attraction between masses
• gravity attracts all masses
• gravity makes all things fall towards the ground and gives everything a weight
• mass is the amount of stuff in an object
• weight is the force acting on an object due to gravity. close to earth, the force is caused by the gravitational field around the earth
• gravitation field strength varies with location
• an object has the same mass on earth and moon. but its weight will be different. (moon 1.6N earth 9.8N)
• weight is a force measured in newtons
• a uniform object, which has the same density throughout and is a regular shape, the centre of mass will be at the centre of the object
• weight is measured using a calibrated spring balance or a newton mater
• mass is not a force. measured in kilograms with a mass balance
• mass and weight are directly proportional