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Author Topic: How are the formulae in "why does E=mc2" transposed?  (Read 985 times)

Offline Steve in Kent

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Just trying to get my head around some of the formulae used in "why does E=mc2"
I want to understand the workings of how the formulae were transposed.
Just need an online resources to relearn how to do it.
The last time I had to do this was back in 1976 for my engineering degree.

Any links will be really appreciated,  especially if someone has already done the steps for the specific formulae used in the book.

Thanks,

Steve
« Last Edit: 24/06/2016 16:38:13 by chris »


 

Offline PmbPhy

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Just trying to get my head around some of the formulae used in "why does E=mc2"
I want to understand the workings of how the formulae were transposed.
Just need an online resources to relearn how to do it.
The last time I had to do this was back in 1976 for my engineering degree.

Any links will be really appreciated,  especially if someone has already done the steps for the specific formulae used in the book.

Thanks,

Steve
Hi Steve,

Welcome to the forum!  :)

I don't know what you mean by needing help transposing formulae. If you're trying to understand where E = mc2 came from then that's something I can help you with. In fact I know the book you're referring to. I have a copy of it myself. I thought it would help me learn more about the subject but it turned out that I know the subject as well, if not better, than the author. I'm not being arrogant here. I'm a physicist myself. I chose to specialize in relativity and the one topic in relativity that I chose to be an expert at is the concept of mass and the meaning of E = mc2.

So I'll help you as much as I can so long as you're serious about the subject (and not a nutcase.. lol).
 

Offline hamdani yusuf

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Just trying to get my head around some of the formulae used in "why does E=mc2"
I want to understand the workings of how the formulae were transposed.
Just need an online resources to relearn how to do it.
The last time I had to do this was back in 1976 for my engineering degree.

Any links will be really appreciated,  especially if someone has already done the steps for the specific formulae used in the book.

Thanks,

Steve
I think you can start from here
https://en.wikipedia.org/wiki/Mass%E2%80%93energy_equivalence#Mass.E2.80.93velocity_relationship
 
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Offline Semaphore

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Re: How are the formulae in "why does E=mc2" transposed?
« Reply #3 on: 24/06/2016 17:58:04 »
I saw a derivation of E=MC2 which just depended on the observational evidence that light has momentum, and using conservation of energy and momentum in a thought experiment.
 

Offline Steve in Kent

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Re: How are the formulae in "why does E=mc2" transposed?
« Reply #4 on: 24/06/2016 18:29:23 »
I don't know what you mean by needing help transposing formulae.

Thank you for the response.

For instance, how to get from C/Sqrt(c sqrd - v sqrd)  to 1/Sqrt(1 - v sqrd/c sqrd)

Sorry, don't know how to get symbols 

I could just accept them as fact, but I would like to understand the process itself.

Steve
 

Offline PmbPhy

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Re: How are the formulae in "why does E=mc2" transposed?
« Reply #5 on: 24/06/2016 19:47:33 »
I don't know what you mean by needing help transposing formulae.

Thank you for the response.

For instance, how to get from C/Sqrt(c sqrd - v sqrd)  to 1/Sqrt(1 - v sqrd/c sqrd)

Sorry, don't know how to get symbols 

I could just accept them as fact, but I would like to understand the process itself.

Steve

Divide the numerator and denominator by c. When you bring 1/c inside the square root sign you have to square it, i.e. (1/c)sqrt{c2 - v2} = sqrt{(1/c2)[c2 - v2 ]}

Try finishing the rest yourself. If you'd like to see a complete derivation of E = mc2 then you can see the derivation I wrote and placed on my website at: http://www.newenglandphysics.org/physics_world/sr/mass_energy_equiv.htm
 

Offline Steve in Kent

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Re: How are the formulae in "why does E=mc2" transposed?
« Reply #6 on: 25/06/2016 05:28:11 »
I don't know what you mean by needing help transposing formulae.

Thank you for the response.

For instance, how to get from C/Sqrt(c sqrd - v sqrd)  to 1/Sqrt(1 - v sqrd/c sqrd)

Sorry, don't know how to get symbols 

I could just accept them as fact, but I would like to understand the process itself.

Steve

Divide the numerator and denominator by c. When you bring 1/c inside the square root sign you have to square it, i.e. (1/c)sqrt{c2 - v2} = sqrt{(1/c2)[c2 - v2 ]}

Try finishing the rest yourself. If you'd like to see a complete derivation of E = mc2 then you can see the derivation I wrote and placed on my website at: "deleted because I cannot post links"

Excellent, thank you.

I've also found "Helping Engineers Learn Mathematics" (HELP) which I will study.

Steve
 

Offline Steve in Kent

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Re: How are the formulae in "why does E=mc2" transposed?
« Reply #7 on: 29/06/2016 10:15:00 »
Wow, there is so much I have forgotten.

Still haven't managed to sort this, but will keep trying.
 

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Re: How are the formulae in "why does E=mc2" transposed?
« Reply #7 on: 29/06/2016 10:15:00 »

 

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