What causes mass and weight?

Answer 1

Weight is mass under acceleration.

Everything in the universe has mass (physicists are still trying to work out if photons have mass, but that is a different question). Newton's Laws state that F=M*A. Since earth's gravity is 9.81m/s/s, your mass is [your weight] divided by 9.81 [earth's gravitational acceleration].

Answer 2

This is a simple looking question with a very complex answer. Mass is easiest to think of as a measure of the amount of matter there is in an object or substance. This definition breaks down somewhat when considering Einstein's theory of relativity which states that "as speed increases, mass also increases" this is derived from the equation E=mc2 which also states that "If an object's velocity is the speed of light then it's mass becomes infinite". However for this answer we will assume that mass is constant based on the matter within an object. Mass is measured on earth in kilograms (kg).

Weight on the other hand is a more debated topic, weight is caused by gravitational force and is measured in Newtons. The relationship between kilograms and newtons on earth is approximately 0.1kg = 1N. Gravity is a very weak force compared to other forces (just jump a few inches off the ground and you'll see what I mean) but remains the most unusual. A common theory at the moment is that gravity acts in a similar way to light, with any object with mass emitting gravition particles which attract other objects. There are problems with this theory but currently it is considered the most likely. Weight also changes depending on what planet your on.

In short

Mass is caused by the energy applied to an object with a certain amount of matter

Weight is caused by the application of gravity to an object with mass

Answer 3

Mass is a measure of the amount of matter in an object, while weight is the force of gravity acting on that object's mass. Mass remains the same regardless of location, but weight can vary depending on the strength of the gravitational pull.