Answer:
1-[tex]\frac{-2kQq}{x^{3} }[/tex]
2-18*10^18
3-Decrease
Step-by-step explanation:
1-The instantaneous rate of change of the force is the derivate
So: F'=kQq(-2x^-3)=[tex]\frac{-2kQq}{x^{3} }[/tex]
Q, q and k are constants, so we can apply the power rule to compute the derivate
2-By sustitution, we get
F'=[tex]\frac{-2*9*10^9*1*1}{0.001^{3} }[/tex]=18*10^18
3- The magnitude will decrease with the separation because we are dividing a constant by larger and larger values.