Help Me Find Mass-Energy Equivalence Formula!

[cobi18]

Simple algebra to find the strict mass–energy equivalence formula, and I can't do it!

find ((m^2)*(c^4)=(E^2)-(p^2*c^2)) from (E=m*c^2*y) (p=m*y*v)
(y=1/(1-(v^2/c^2))^(1/2))


Yeh i can find the m^2c^4 parts and the E^2 obvioulsy. but then i am stuck with E^2(v^2/c^2) when instead i want (p^2c^2). If anyone could help that would be great!

 

[Doc Al]

Yeh i can find the m^2c^4 parts and the E^2 obvioulsy. but then i am stuck with E^2(v^2/c^2) when instead i want (p^2c^2).

Use E=m*c^2*y again.

 

[cosmic dust]

Use E=m*c^2*y again.

That will not solve anything... The formula for the momentum has to be used. I recommend you to start with "p = γmv" and find "v" as a function of "p", then find "γ" as a function of "p" and finaly replace "γ" in "E=γmc²" with what you have found.

 

[Doc Al]

That will not solve anything...

Sure it will. It's the first step:
-step 1: use the formula for E as I described

The formula for the momentum has to be used.

Of course it does. That's the second step:
-step 2: then rewrite the results in terms of p

 

[cosmic dust]

OK, I thought you had say to use the formula for E twice, sorry...