Gravity and weight

• All objects with mass produce a gravitational field. The larger mass an object has, the larger the gravitational field it has
• Gravity is a force of attraction between all objects
• Gravity is a non contact force because the two are ejects do not need to be touching
• Gravity is a vector quantity
• Mass tells us how much matter an object has in it
• The unit of mass is kilogram (kg)
• The unit of weight is the newton (N)
• Weight of an object depends on where it is
• At the surface of the earth the gravitational force is 9.8N/Kg.
• Gravitatiomeal field strength is the force of gravity acting on an object. And it has the symbol (g)
• The gravitational field strength is a measure of the force of gravity in a particular location
• Equation for weight:

  • Weight (N) = Mass (kg) x gravitational field strength (N/Kg)
• The weight of an object is directly proportional to the mass of the object
• We can determine an objects weight using a calibrated spring-balance
• Newtonmeter = calibrated spring balance
• Gravitational field strength depends on where you are
• The gravitational field strength of the moon is 1.6N/Kg
• The weight of an object (the force due to gravity) can be considered to act at a single point called the centre of mass.