Finding mass only given electrons

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    Electrons Mass
AI Thread Summary
A neutral balloon gains 42 electrons when rubbed on a head, prompting a calculation of the mass increase. The mass of an electron is approximately 9.11 x 10^-31 kg, leading to a total mass increase of about 3.82 x 10^-29 kg for the balloon. The discussion highlights confusion regarding the electric field and force calculations, but ultimately, the solution simplifies to determining the weight of the electrons. Participants emphasize the importance of focusing on the mass of the electrons rather than overcomplicating the problem. The thread concludes with the realization that the calculation is straightforward once the mass of an electron is understood.
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Homework Statement


A neutral balloon picks up 42 electrons when it is rubbed on someone's head.
Calculate how much the mass of the balloon has increased.


Homework Equations



E=F/q
F=kq1q2/r^2

The Attempt at a Solution


Well, I do know the answer is 3.82 x 10^-29.
Using E=F/q q=1.6x10^-19 but I don't know where the electric field comes from.
Using F=kq1q2/r^2 both q's= 1.6x10^-19 and k=9x10^9 but I don't know where the distance comes from.
I feel like I haven't been given enough information...? Please help.
 
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What's the mass of an electron? (Look it up!)
 
I think you are over-complicating this. How much do 42 electrons weigh?
 
Yeah, never mind I just got it
 

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