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hanii
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hey guys ...i've got a doubt..
when there is no absolute rest in the universe...how is rest mass defined?
when there is no absolute rest in the universe...how is rest mass defined?
There's always a frame in which the body (or its center of mass) is at rest. Nothing 'absolute' needed.hanii said:hey guys ...i've got a doubt..
when there is no absolute rest in the universe...how is rest mass defined?
ZealScience said:Yes there is no absolute rest, because particles are all moving fast. Unless reach absolute zero which would break the second law of thermodynamics or the uncertainty principle. But discussing relativity, I think, we talk more generally about macroscopic objects in reference frames.
bcrowell said:"Absolute rest" in this context means being able to define whether an object is at rest without reference to anything external. Even if we could cool an object down to absolute zero, it wouldn't be at "absolute rest" in this sense.
ZealScience said:Of course it depends on reference frames, but with temperature particles are moving fast! The mass of electron that measured by scientists is the mass of moving electrons. They are not interested in inertial mass of electrons.
Doc Al said:There's always a frame in which the body (or its center of mass) is at rest. Nothing 'absolute' needed.
hanii said:how is this equation derived?
jtbell said:[tex]E^2 = (pc)^2 + (mc^2)^2[/tex]
Rest mass is the mass of an object when it is stationary or at rest. It is an intrinsic property of an object and is not affected by its motion or velocity.
Apparent mass is the mass of an object as it is observed by an outside observer. It takes into account the object's motion and velocity and is affected by factors such as relativistic effects.
The main difference between rest mass and apparent mass is that rest mass is an intrinsic property of an object, while apparent mass is the observed mass of an object taking into account its motion and velocity.
Rest mass is typically measured using a mass balance or by using the equation E=mc^2, where E is energy, m is mass, and c is the speed of light.
As an object's velocity increases, its apparent mass also increases due to relativistic effects. This means that the mass of an object is not constant and can change depending on its motion and velocity.