RuSkaya

10+ Year Member
5+ Year Member
Jul 18, 2008
328
0
0
Queens, NY
Status
Medical Student
I am confused with the following idea (it was in an answer explanation on this TBR test):


given a reaction and conservation of energy,

(energy of reactant 1) + (energy of reactant 2) = (energy of product 1) + (energy of product 2) - mc^2

I don't understand why mc^2 is being subtracted from the product side. I understand mc^2 to be ADDITIONAL energy as a result of mass being converted to it... so shouldn't it be added to the final energy?
 

dingyibvs

Psych!
10+ Year Member
Sep 13, 2007
5,444
8
251
Florida
Status
Medical Student
I am confused with the following idea (it was in an answer explanation on this TBR test):


given a reaction and conservation of energy,

(energy of reactant 1) + (energy of reactant 2) = (energy of product 1) + (energy of product 2) - mc^2

I don't understand why mc^2 is being subtracted from the product side. I understand mc^2 to be ADDITIONAL energy as a result of mass being converted to it... so shouldn't it be added to the final energy?
Right, mc^2 is the additional energy, so if you don't subtract it, the two sides will no longer be equal as the products will have an extra mc^2 joules of energy.