Whats the difference between the mass and weight of an object?
Mass is measured in grams etc and is how heavy something is when no force is acting upon it. Weight is the amount of mass * gravity and should be measured in newtons. Your mass can never change, but your weight can depending on how strong gravity is. Eg on the moon gravity is about x5 weaker than earth, as a result you weigh x5 less than you do on earth.