# Does an A mass always give the same amount of energy?

In summary, when an object with a 5kg mass is traveling at the speed of light, its energy is 450.000.000.000 J. However, if you mix the object with anti-matter, the energy of the mass will ONLY be E&M energy, and will not create mass.

hello people,

i am new at physics and i have a question that you will be able to answer !

well,
supposedly we have a subject with 5kg mass...
if we make it travel at the speed of light we will get E = 5 x 300.000 x 300.000 = 450.000.000.000 J is this the same amount of energy it will give off if we mix it with anti-matter?

P.S (soory for the noobie question i just would like to learn more and more ! )

Learning is always good; great question.

A 5kg mass has (E=mc^2) energy in the form of its rest mass. If it were to perfectly annihilate into energy (from anti-matter presumably) then all of this energy would be released (as photons).

You can't accelerate any massive body TO the speed of light - you can only get them close to the speed of light. If you do that however, you drastically increase the energy of the body to significantly more than the rest mass. At relativistic speeds, E=mc^2 isn't the total energy, just the rest mass energy.
If you add the gamma (lorentz) factor, E='gamma'*mc^s -> that represents the energy stored in the net mass (the relativistic mass); but still does not include the kinetic energy.

lzkelley said:
A 5kg mass has (E=mc^2) energy in the form of its rest mass. If it were to perfectly annihilate into energy (from anti-matter presumably) then all of this energy would be released (as photons).

Does this mean that mixing matter with anti-matter can only give off electromagnetic energy?

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When we say "at rest" (invariant mass) we mean when the aren't any forces on the mass?(i read it on wiki and understood nothing)

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What's net mass??

rest mass, is the mass in a reference frame in which the object is stationary. if you see an object moving past you, it has a mass (which i was calling "net mass") that is larger than its rest mass. Does that make sense?
(If you put forces on the object - then it makes it even more complex - but don't worry about that).

If you mix matter with anti-matter, if they collide / annihilate, they will give off only and purely E&M energy. Two things are noteworthy:
first, often the E&M energy will reform into mass; second, matter and anti-matter don't always annihilate.

hello people,

i am new at physics and i have a question that you will be able to answer !

well,
supposedly we have a subject with 5kg mass...
if we make it travel at the speed of light we will get E = 5 x 300.000 x 300.000 = 450.000.000.000 J is this the same amount of energy it will give off if we mix it with anti-matter?

P.S (soory for the noobie question i just would like to learn more and more ! )

I think you are thinking any object posesses mass moving at speed of light will have E=mc^2. E=mc^2 have nothing to do with object moving at the speed of light. It just saying if one convert pure mass into pure energy, that's what you should get. I think if an object with near c speed will still have conventional kinetic energy 1/2mc^2. Particle accerlator graph show that energy spike up to ifinity near speed of light. Of course that is due to scientists keep adding energy to the particle.

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lzkelley said:
rest mass, is the mass in a reference frame in which the object is stationary. if you see an object moving past you, it has a mass (which i was calling "net mass") that is larger than its rest mass. Does that make sense?
(If you put forces on the object - then it makes it even more complex - but don't worry about that).

If you mix matter with anti-matter, if they collide / annihilate, they will give off only and purely E&M energy. Two things are noteworthy:
first, often the E&M energy will reform into mass; second, matter and anti-matter don't always annihilate.

so the mass of an object is different when moving and different when its stationary??

and what kind of mass will E&M energy create??

thanx for you assisstance friend

## 1. Does the mass of an object affect its energy?

Yes, the mass of an object is directly related to its energy. According to the famous equation E=mc^2, the energy of an object is equal to its mass multiplied by the speed of light squared. This means that even a small change in the mass of an object can result in a significant change in its energy.

## 2. Is the energy of an object always directly proportional to its mass?

No, while mass does play a crucial role in determining the energy of an object, there are other factors that can also influence an object's energy. For example, the velocity of an object can also affect its energy, as seen in the kinetic energy equation KE=1/2mv^2.

## 3. Can an object with a small mass have a high amount of energy?

Yes, the mass of an object is not the only factor that determines its energy. As mentioned before, the speed or velocity of an object also plays a role. For example, a bullet with a small mass but high velocity can have a significant amount of energy.

## 4. Is the energy of an object with a high mass always greater than that of an object with a low mass?

Not necessarily. While a higher mass generally means a higher energy, it is also essential to consider the speed or velocity of the object. An object with a low mass but high velocity can have more energy than an object with a high mass but low velocity.

## 5. Can an object with a negative mass have negative energy?

No, negative mass is a hypothetical concept and does not have a confirmed existence in our physical world. Therefore, the idea of negative energy associated with negative mass is also theoretical and has not been observed or proven.