Which sphere will be heavier: one with a charge of 0.0000001C or one with 100C?

[astro2cosmos]

it may bit a fuzzy problem but still i have this confusion i.e suppose i have two sphere of same radius & all physical & material properties are same but 1st sphere has a charge of 0.0000001C & another have 100C. and if i measure the weight of both then which will be heavier?

 

[HallsofIvy]

No, charge has no mass or weight.

 

[Bob S]

hello Astro-
One gram molecular weight (GMW) of electrons has a mass of 0.0005446 grams. 100 C of electrons has a mass about 96 times less. So a sphere with +100 C of charge will have a lesser mass than an "identical" sphere with -100C, because electrons have a negative charge.

"identical" means the same number of protons and neutrons.
Bob S

 

[astro2cosmos]

hello Astro-
One gram molecular weight (GMW) of electrons has a mass of 0.0005446 grams. 100 C of electrons has a mass about 96 times less. So a sphere with +100 C of charge will have a lesser mass than an "identical" sphere with -100C, because electrons have a negative charge.

"identical" means the same number of protons and neutrons.
Bob S

hey bob!
can u please explain that how 100 C of electrons has a mass about 96 times less.

 

[Bob S]

hey bob!
can u please explain that how 100 C of electrons has a mass about 96 times less.

Sure. A GMW (gram molecular weight) of protons has a mass of 1 gram, and contains 6,02 x 10²³ protons (approximately). The mass of an electron has a mass 1836 times less (remember hydrogen atom). The charge on an electron is 1.6 x 10^-19 Coulomb, so a Coulomb contains 6.25 x 10¹⁸ electrons. So a GMW of electrons contains 96,320 Coulombs of electrons.
Bob S

 

[Vanadium 50]

I think you'll need to supply more information about what exactly you're trying to calculate here. Is it the mass of electrons? (And remember, if I have a positive charge, I'm removing electrons). Is it the relativistic mass equivalent of the potential energy from assembling this charge configuration? Is it something else?

 

[Bob S]

[STRIKE][/STRIKE]

I think you'll need to supply more information about what exactly you're trying to calculate here. Is it the mass of electrons? (And remember, if I have a positive charge, I'm removing electrons). Is it the relativistic mass equivalent of the potential energy from assembling this charge configuration? Is it something else?

Hi Vanadium50-
This is calculating the rest mass of each sphere in isolation. [STRIKE][STRIKE][STRIKE]When the two spheres are brought close together, the Coulomb force is about [STRIKE]8[/STRIKE]9 billion (9 x 10⁹) Newtons at 100 meters, so perhaps a kilometer might be better[/STRIKE][/STRIKE][/STRIKE].
[STRIKE]Because the positive sphere is missing 100 Coulombs of electrons, and the negative one has 100 Coulombs of extra electrons,[/STRIKE] the more negatively charged sphere has more mass.
Bob S

 

[Vanadium 50]

Bob, I think it's best for the OP to tell us what he is trying to calculate rather than guessing.