Calculating Electric Force with Coulomb's Law: Glass and Rubber Ball Example

[gotpink74]

Homework Statement

What is the electric force between a glass ball that has +2.8 µC of charge and a rubber ball that has -4.8 µC of charge when they are separated by a distance of 4.5 cm?


2. Homework Equations

F=k*Q1*Q2/r^2

3. The Attempt at a Solution
-59.6507
-8.8888888.889
4.4380e12

 

[gotpink74]

i got -59.7333 but it is wrong HELP please