E=mc2 (1 Viewer)

[Cheezy-G]

Hi I was just wandering if anyone could help me understand the idea of mass and energy being interchangable. I'e read our text book but I don't seem to get it.

 

[Xayma]

This isn't really much of an issue in space but becomes more so in Quanta to Quarks.

Energy and Mass are interchangable, that is, mass can be converted to kinetic energy, heat energy (as is the case in nuclear reactors) or various other forms of energy. Energy on the other hand can be converted to mass (eg when you go faster, or during particle collisions at very high speeds).

The ratio is:

E=mc²

That is Energy (in Joules) is equal to the mass (in kilograms) multiplied by the speed of light squared (in ms^-1)

Eg 1kg of matter transformed into energy would yield:

9*10¹⁶ J of energy (however it isnt converted on such a large scale as 1kg except in stars).

As to the exact mechanics of how they interchange, it is far outside the realms of High School (and afaik undergraduate) Physics and I can't help you there.

 

[AntiHyper]

Well that formula only applies to stationary object (constant velocity with the observer)
In actual fact it's E=KEmc² , where KE stands for Kinetic Energy.

 

[m_isk]

so im 95kg..my energy is 95*3x10^16?? uhuh its closer to 0.00.... nah seriously is there some kind of extraordinary situation where the interchangeability of mass and energy applies??

 

[repressed]

In nuclear bombs is a good place where the formula applies. THe bombs dropped on japan changed less than a kilo of matter to energy, so technically if you changed your 95kg into energy you could blow up a good portion of australia

 

[Xayma]

Well considering to change his 95kg of matter into energy completly would require 95kg of antimatter for him to hug.

But 95*9*10¹⁶
=8.55*10¹⁸ J

So the energy is about 8000 times that of a hurricane. And about 90% that of Krakatoa.

 

[jm1234567890]

Well that formula only applies to stationary object (constant velocity with the observer)
In actual fact it's E=KEmc² , where KE stands for Kinetic Energy.

you mean E=KE + mc²

And this is all speaking in non-reletavistic speeds

reletavistic definition is here

http://hyperphysics.phy-astr.gsu.edu/hbase/relativ/releng.html