Derive lorentz transform for energy

In summary, the conversation discusses the derivation of the relation E' = \gamma (E + \beta p c) and its significance in the context of Lorentz transformations. The conversation also touches upon the importance of understanding the distinction between unprimed and primed variables in the equation. The final solution is achieved by using the Lorentz transform for velocities and recognizing that p' = \gamma p. Overall, the conversation provides a clear explanation and solution to the problem at hand.
  • #1
gboff21
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0

Homework Statement


Derive the relation:
[itex]E' = \gamma (E + \beta p c)[/itex]

Homework Equations


[itex]p' = \gamma p \\
E^{2} = p^{2} c^{2} + M^{2}c^{4}[/itex]

The Attempt at a Solution


start off with stationary frame S [itex]E=mc^{2}[/itex]
then in moving frame S' [itex]E'^{2} = p'^{2} c^{2} + E^{2}[/itex]:
lorent transform momentum:
[itex]E'^{2} = \gamma^{2} m^{2} v^{2}c^{2} + E^{2}[/itex]
and that's as far as I get!
 
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  • #2
##E=\gamma mc^2##

That "p", in the equation you are supposed to prove, is unprimed.
Is that significant?
 
  • #3
Yes the p is supposed to be unprimed.

I've solved it now. Thanks anyway.
Here it is for anyone who's having the same problem:
You start off (or derive it as I had to, to understand it) with the lorentz transform for velocities in two frames [itex]u = \frac{u'+v}{1+frac{uv}{c^{2}}}[/itex]
Know that [itex]E'=\gamma m_{0}c^{2}[/itex] because in the stationary frame S, only rest mass provides energy.
You expand out gamma with u' given above and recognise that [itex]p'=\gamma p[/itex]
simplify and you get an answer!
 

1. How is the Lorentz transform related to energy?

The Lorentz transform is a mathematical equation that describes the relationship between space and time in Einstein's theory of special relativity. It includes a term for energy, which shows how energy is affected by changes in velocity and reference frames. This equation is crucial for understanding the concept of relativistic energy, which takes into account the effects of high speeds on the energy of an object.

2. What is the significance of the Lorentz factor in the energy equation?

The Lorentz factor, denoted by the symbol γ (gamma), is a key component of the Lorentz transform for energy. It represents the ratio of an object's relativistic mass to its rest mass, and it increases as the object's velocity approaches the speed of light. This factor is important because it allows us to calculate the amount of energy an object has at different velocities, and it shows that an object's energy increases significantly as it approaches the speed of light.

3. How does the Lorentz transform for energy differ from the classical equation for kinetic energy?

The classical equation for kinetic energy, KE = 1/2mv^2, only applies to objects moving at speeds much lower than the speed of light. The Lorentz transform for energy, on the other hand, takes into account the effects of special relativity and applies to objects moving at any speed. It includes the Lorentz factor and the rest energy of an object, which is equivalent to its mass multiplied by the speed of light squared (E = mc^2).

4. Can the Lorentz transform for energy be derived from the Lorentz transform for space and time?

Yes, the Lorentz transform for energy can be derived from the Lorentz transform for space and time. By combining the equations for time dilation and length contraction with the principle of conservation of energy, we can arrive at the Lorentz transform for energy. This shows that energy is a fundamental component of space and time in special relativity.

5. How does the Lorentz transform for energy impact our understanding of the universe?

The Lorentz transform for energy is a crucial part of Einstein's theory of special relativity, which has revolutionized our understanding of the universe. This equation shows that energy and mass are interrelated and that they can be converted into each other. It also explains the observed effects of time dilation and length contraction at high speeds. Without the Lorentz transform for energy, our understanding of the universe and its fundamental laws would be incomplete.

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