- #1

Astraithious

- 20

- 0

## Homework Statement

Imagine you could place 1g of electrons 1.0 m away from another 1g of electrons. calculate the electrical force and gravitational force between them.

## Homework Equations

fe= kQ1Q2/r^2

fg=Gm1m2/r^2

## The Attempt at a Solution

So the number of electron is

N= 0.001 / 9.1*10^-31 = 1.074*10^27 electrons

The the total charge is

q= N*e

= 1.074*10^27 * (1.6*10^-19)

= 1.718*10^8 coulomb so plugging that into fe= kQ1Q2/r^2 i get 2.7 x 10^10 n roughly for the force between them, however this seems to be incorrect as the answer given is 2.9 x 10^26

second part was easy and comes to 6.67^10^-17

my understanding of the ratio is

F_e/F_g=(k*e^2/r^2)/(G*m_e^2/r^2)

=k*e^2/G*m_e^2 [/B]

which comes out to roughly 4.2 x 10^42 depending on the rounding you did on the constants.

so using that ratio on 6.67 x 10^-17 the answer isn't either mine nor the one given on the work sheet.

Any help would be great, I'm sure its theory I'm misunderstanding but perhaps the math is off too. thanks!