Distinguish between the mass of an object and the object's weight?

Answer 1

The mass of an object is unchanging relative to the local gravity. The weight of an object is relative to the strength of the gravity in which it is weighed. The metric unit gram is a measure of mass. The English system unit a pound is a measure of weight. Something that has a mass of 1 kilogram on Earth has the same mass on the Moon, but two entirely different weights. On Earth, a 1 kilogram mass weighs approximately 2.2 pounds. On the Moon, where the gravity is about 1/6th that of Earth, the same 1 kilogram mass weighs only a little over 1/3 of a pound. A weight of an object is a consequence of its having a mass, in the presence of a gravitational field. A mass is a property of the object, won't change unless the integrity of the object is affected. Its weight, though, is a consequence of the object being nearby another (massive) object, in most contexts that will be the (surface of the) Earth.

Say a Bowling ball weights 3 kilograms. This a short for saying 'on the surface of the Earth, this bowling ball is atracted to the Earth with a force of 3 kilograms', or, more properly said, with a force equal to 3 x 9,8 Newton (Newton is the proper measuring unit for force).

If that bowling ball was on the surface of the Moon, it would weight about 0,5 kilograms, one sixth more or less of its weight on the Earth. Yet, its mass would still be 3 kilograms.

If you were to hang vertically (somehow) from a rope your bowling ball, so it stands still, the rope would have to be able to resist 3 kilos in the Earth, in the Moon a rope that can take 0,5 kg would be enough.

But say you try to throw the ball away, doing it the way hammer throw athletes do in the Olympics, swinging it around you in circles, then releasing it. While you make it turn around you (horizontally), the tension in the rope depends on the speed at which you make it turn and *the mass* of the ball. If you make it turn at the same speed (with the same rope length), the tension on the rope will be same on Earth and on the Moon. But the distance your throwing attempt will reach would be different, since it depends on *the weight* of the ball. On the Moon, all being equal (speed in swinging the ball, length of the rope, angle of your throw), you would reach 6 times farther than in the Earth.

Other experiments you might perform on the Moon or on the surface on other unknown space bodies, might involve measuring the period of oscillations of your bowling ball when attached to string, or playing 'pool' with another ball of known mass and measuring speeds and angles after and before their collision. This is because the physics principles involved in those experiments (preservation of energy, preservation of linear momentum, respectively), do involve the mass of the objects, not their weight.

Answer 2

The mass of an object is a measure of the amount of matter it contains, usually expressed in kilograms or grams. Weight, on the other hand, is the force of gravity acting on an object and is dependent on the mass of the object and the acceleration due to gravity. Mass is an intrinsic property of an object, while weight varies based on the gravitational pull.

Answer 3

Mass is the amount of matter in an object, while weight is the amount of effect gravity has on an object.

Answer 4

mass is how much matter or "stuff" is in an object but weight is how much matter is in an object with the effects of gravity

Answer 5

Your mass does not change even if you are in outer space. But you will have no weight.