/sci/ - Science & Math

[Anonymous No.4538646]

sup /sci/ just read something in my book and it doesn't seem to make sense to me, but I'm probably just having a retard moment
in nuclear fission, the mass of the nucleus is less than the mass of the separated nucleons right?
so when fusion happens, why is energy realised if energy is inputted to overcome the binding energy?

i know i sound like an absolute retard, but help is appreciated

pic unrelated

[Anonymous No.4538654]

Because E=mc^2
It is a very obscure equation. You have probably never heard of it.

[Anonymous No.4538659]

you don't "overcome" binding energy

you release it

mass before fusion = mass after fusion + little bit of mass converted to energy

[Anonymous No.4538673]

>>4538654
thats only a special case of E^2-(pc)^2=(m_0c^2)^2 for when the particle is at rest.

[Anonymous No.4538684]

>>4538659
i get it for fusion, just not fission

[Anonymous No.4538689]

>>4538684
for fission heavier elements have more mass, so it goes the other way

around the element iron there's a maximum binding energy

this means to split iron takes more energy than any other element. so to create iron, either by fusing lighter elements, or splitting heavier ones releases energy

so pic related is kind of upside down in terms of energy available

[Anonymous No.4538692]

binding should properly be referred to as splitting energy

[Anonymous No.4538716]

so essentially in fisison
mass of reactants > mass of products
mass of reactants = mass of products + mass defect

mass defect = energy released (E=mc^2)

so the energy released comes from the energy binding the nucleons together that no longer needs to be?
and the input of energy from the thermal neutron is just like the "activation" energy to start the reaction?

[Anonymous No.4538734]

(ignoring post, looking at pic)

What's also kind of amazing is how much physics you can understand with relatively little math. For example, special relativity requires nothing more than high school level algebra.