Suppose a charge +q on Earth's surface and another +q charge is placed on the surface of the Moon. (a) Calculate the value of q required to balance the gravitational attraction between Earth and Moon.

Explanation

Mass of the earth `m_(E)=5.9xx10^(24)kg`
Mass of the moon `m_(M)=7.9xx10^(22)kg`
Charge placed on earth and moon is q
To find: The amount of charge required to balance to gravitational attraction between earth & moon =?
If q is the charge placed on the moon & earth, then
Formula: `(1)/(4piepsi_(0)).(qxxq)/(r^(2))=G.(m_(E)xxm_(M))/(r^(2))`
`(1)/(4piepsi_(0))=9xx10^(9)`
`G=6.6xx10^(-11)Nm^(-2)kg^(-2)`
`4piepsi_(0)=0.11xx10^(-9)` or
`q=sqrt(4piepsi_(0)Gm_(E).m_(M))`
`=sqrt(0.11xx10^(-9)xx6.6xx10^(-11)xx5.9xx10^(24)xx1.9xx10^(22))`
`q=sqrt(33.84xx10^(26))`
`q=5.82xx10^(13)C`.