Two balls, each with a mass of 0.813 kg, exert a gravitational force of 8.38 x 10^-11 N on each other.How far apart are the balls? The value of the...

Let the distance between the two balls be d and their masses be m1 and m2. Then by gravitational law, the force of attraction F,between them is:

F =G*m1*m2/d^2 .

By data,F = 8.38 *10^(-11)N,  m1 = m2 = 0.813 kg , G =6.673 x 10^-11 N m^2/kg^2 and d is to be determined.

Therefore,

d =sqrt( G*m1*m2/F ). Substituting the values from data,

d = sqrt{(6.673 x 10^-11)(0.813)^2/(8.38*10^-11)}

=0.725486104 m is the required distance between the two masses, where the gravitational attractional   force  between them  is as given.