Two charges are separated by a distance d = 5 m. The charge q1 has a charge of q1= 7.0 µC (microcoulombs) and q2 has a charge of q2= 6.8 µC. What is the force between the charges?

Answer 1

Use Coulmb's Law

F = k*q1*q2/r^2

k is a constant you should know or look up.

Answer 2

f=9*10^9*q1q2/r^2
f=9*10^9*7*6.8/[5]^2
f=9*10^9*7*6.8/25
hence
,f=17136*10^6