Difference between Mass and Weight?

In summary, weight is the force that the Earth exerts on an object's mass. This is a distinct definition of weight that is different from the feeling of weightlessness experienced in a falling elevator or during skydiving or space travel. In legal and colloquial terms, weight is often used as a synonym for mass.
  • #1
Jadaav
175
1
What is the difference between Mass and Weight?

Because i often get confused about it.

It's concerned about Newton's second law.

I'm trying to learn it by myself.:)
 
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  • #2
Mass is how much stuff there is in an object - it doesn't change.
Weight is the force that the Earth pulls on the mass with.

So on the moon you would have the same mass, but only 1/6 the weight.
In a falling elevator you would be weightless but not massless.
 
  • #3
mgb_phys said:
Weight is the force that the Earth pulls on the mass with.
In a falling elevator you would be weightless but not massless.
These are two rather distinct definitions of weight. The gravitational force that the Earth exerts on a person in a falling elevator is no different than the force that the Earth exerted on this unfortunate person while he was waiting for the elevator. In this context, weight is just a synonym for gravitational force.

We call the person in the falling elevator "weightless" because that person truly does feel something quite different than the person waiting for the elevator. The same feeling of weightlessness occurs when a skydiver first jumps out of an airplane and when an astronaut is in a quiescent (non-thrusting) orbiting vehicle. That second definition of weight is called apparent or scale weight.

Finally, legally and colloquially, weight is a synonym for mass rather than having units of a force. In this context, a one pound can of peas weighs one pound anywhere on the Earth, in a space station, on the Moon, and in deep space.
 
  • #4
Thanks for the answers guys:)
 
  • #5
mgb_phys said:
Weight is the force that the Earth pulls on the mass with.

Some discrepancy here:

So on the moon you would have the same mass, but only 1/6 the weight.

Assuming it is force that Earth pulls me with, when on Moon surface I should weight much less than that, about 1/3640 :tongue2:
 

What is the difference between mass and weight?

Mass and weight are two commonly confused terms in science. While they are related, they have distinct meanings and units of measurement.

How is mass defined?

Mass is a measure of the amount of matter in an object. It is an intrinsic property of an object and does not change with location or environment. The standard unit of mass is kilograms (kg).

How is weight defined?

Weight is a measure of the force of gravity acting on an object. It is a relative quantity and can change depending on the location and gravitational pull. The standard unit of weight is Newtons (N).

How are mass and weight related?

Mass and weight are related through the equation F = ma, where F is the force of gravity, m is the mass, and a is the acceleration due to gravity. This means that weight is directly proportional to mass.

Why is it important to understand the difference between mass and weight?

Understanding the difference between mass and weight is crucial in accurately measuring and describing objects. It also helps in understanding the laws of physics, such as Newton's second law of motion, which relates mass, force, and acceleration.

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