Mass-Energy Conservation: E/m=c^2

In summary, the conversation explains the equation E=mc^2 and how rearranging it results in the ratio of energy to mass being equal to the square of the speed of light. It is then discussed that this relationship only holds when the particle is at rest, and the question is raised about whether photons satisfy the full equation. It is confirmed that photons do indeed satisfy the equation, despite having momentum but no mass.
  • #1
john951007
9
1
We know the equation E=mc^2 which correlates energy to mass.
If we rearrange the equation:
E/m = c^2 , it turns into the ratio of energy to mass is the square of the speed of light, does it mean for every particle in the universe, the ratio between the energy of the particle and its mass is the square of the speed of light?
 
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  • #2
correct
 
  • #3
The complete equation is ##E^2/c^2-p^2=m^2 c^2##. So the relationship you wrote holds as long as p=0, in other words for a particle at rest.
 
  • #4
Does photon satisfy the full equation, because photon has momentum but does not have mass?
 
  • #5
yep, the photon does satisfy the full equation.
 

What is the concept of mass-energy conservation?

The concept of mass-energy conservation states that energy cannot be created or destroyed, but can only be converted from one form to another. This includes the conversion of mass into energy and vice versa.

How is the equation E/m=c^2 related to mass-energy conservation?

The equation E/m=c^2, also known as the mass-energy equivalence equation, is derived from Einstein's theory of special relativity and is a fundamental concept in mass-energy conservation. It shows the relationship between mass and energy and how they are interchangeable.

What are some real-life examples of mass-energy conservation?

One example of mass-energy conservation is nuclear reactions, where a small amount of mass is converted into a large amount of energy. Another example is the conversion of chemical energy into thermal energy in a combustion reaction.

How does mass-energy conservation impact our understanding of the universe?

Mass-energy conservation is a fundamental law of physics and is crucial in understanding the behavior and interactions of matter and energy in the universe. It has led to the development of technologies such as nuclear power and has helped explain phenomena like the formation of stars and galaxies.

Are there any exceptions to the law of mass-energy conservation?

Currently, there are no known exceptions to the law of mass-energy conservation. However, some theories, such as the theory of dark energy, suggest that the universe may be expanding at a rate that violates this law. Further research is needed to fully understand these phenomena.

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