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Formula of speed


DimaMazin

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At least the units are right (all too often this isn't the case when someone posts a formula here), but unless it comes from a derivation, it doesn't really have any meaning.

 

that is, how is it any different from: [math]v = c \frac{\sqrt{m'^4+2m'^2m^2}}{m'^2+m^2}[/math]? units cancel correctly again, but I just completely made it up and it really doesn't have much meaning at all.

 

So, where does your idea come from, and what does it really mean?

Edited by Bignose
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Let's see:

 

[math]v = c \frac{\sqrt{m'^2+2m'm}}{m'+m}[/math]

 

and

 

[math]m'= \left ( \frac{1}{\sqrt{1-\frac{v^2}{c^2}}} -1 \right ) m [/math]

 

At first, to keep things from being unwieldy, we'll say that

 

[math] \gamma = \frac{1}{\sqrt{1-\frac{v^2}{c^2}}}[/math]

 

So we can say that

 

[math]m' = m \gamma - m [/math]

 

Putting this into the first equation we get

 

[math]v = c \frac{\sqrt{\left( m \gamma - m \right)^2+2\left (m \gamma - m \right ) m}}{m \gamma - m+m}[/math]

 

[math]v = c \frac{\sqrt{\left( m \gamma - m \right)^2+2\left (m \gamma - m \right ) m}}{m \gamma }[/math]

 

[math]v = c \frac{\sqrt{m^2\gamma^2-2m^2 \gamma + m^2 + 2m^2 \gamma -2m^2}}{m \gamma}[/math]

 

[math]v = c \frac{\sqrt{m^2\gamma^2 - m^2 }}{m \gamma}[/math]

 

[math]v^2 = c^2 \frac{m^2\gamma^2 - m^2 }{m^2 \gamma^2}[/math]

 

[math]v^2 = c^2 \frac{\gamma^2 - 1 }{ \gamma^2}[/math]

 

[math]\frac{v^2}{c^2} = \frac{\gamma^2 - 1 }{ \gamma^2}[/math]

 

[math]\frac{v^2}{c^2} = 1-\frac{ 1 }{ \gamma^2}[/math]

 

[math] \frac{v^2}{c^2} = 1- \left ( 1- \frac {v^2}{c^2} \right )[/math]

 

[math] \frac{v^2}{c^2} = \frac {v^2}{c^2}[/math]

 

[math] v^2 = v^2 [/math]

 

[math]v = v[/math]

 

Hardly an earth-shattering revelation. And not very surprising, considering that your initial equation solving for v relied on a term (m'), that itself relied on the value of v.

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At least the units are right (all too often this isn't the case when someone posts a formula here), but unless it comes from a derivation, it doesn't really have any meaning.

 

that is, how is it any different from: [math]v = c \frac{\sqrt{m'^4+2m'^2m^2}}{m'^2+m^2}[/math]? units cancel correctly again, but I just completely made it up and it really doesn't have much meaning at all.

 

So, where does your idea come from, and what does it really mean?

It comes from a derivation:

total energy2=(mc2)2+(cp)2

Einstein's kinetic energy=m'c2

This formulae I have used.If you have a defined gravitation mass and a defined turned mass into energy then you have a defined speed.Thank you for your discussion.

 

 

 

Let's see:

 

[math]v = c \frac{\sqrt{m'^2+2m'm}}{m'+m}[/math]

 

and

 

[math]m'= \left ( \frac{1}{\sqrt{1-\frac{v^2}{c^2}}} -1 \right ) m [/math]

 

At first, to keep things from being unwieldy, we'll say that

 

[math] \gamma = \frac{1}{\sqrt{1-\frac{v^2}{c^2}}}[/math]

 

So we can say that

 

[math]m' = m \gamma - m [/math]

 

Putting this into the first equation we get

 

[math]v = c \frac{\sqrt{\left( m \gamma - m \right)^2+2\left (m \gamma - m \right ) m}}{m \gamma - m+m}[/math]

 

[math]v = c \frac{\sqrt{\left( m \gamma - m \right)^2+2\left (m \gamma - m \right ) m}}{m \gamma }[/math]

 

[math]v = c \frac{\sqrt{m^2\gamma^2-2m^2 \gamma + m^2 + 2m^2 \gamma -2m^2}}{m \gamma}[/math]

 

[math]v = c \frac{\sqrt{m^2\gamma^2 - m^2 }}{m \gamma}[/math]

 

[math]v^2 = c^2 \frac{m^2\gamma^2 - m^2 }{m^2 \gamma^2}[/math]

 

[math]v^2 = c^2 \frac{\gamma^2 - 1 }{ \gamma^2}[/math]

 

[math]\frac{v^2}{c^2} = \frac{\gamma^2 - 1 }{ \gamma^2}[/math]

 

[math]\frac{v^2}{c^2} = 1-\frac{ 1 }{ \gamma^2}[/math]

 

[math] \frac{v^2}{c^2} = 1- \left ( 1- \frac {v^2}{c^2} \right )[/math]

 

[math] \frac{v^2}{c^2} = \frac {v^2}{c^2}[/math]

 

[math] v^2 = v^2 [/math]

 

[math]v = v[/math]

 

Hardly an earth-shattering revelation. And not very surprising, considering that your initial equation solving for v relied on a term (m'), that itself relied on the value of v.

You have connected the universal formula with the local formula. Good job in the appropriate place.tongue.gif
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