After brushing, fluffy's fur has a charge of +8.0 × 10-9 coulombs and her plastic brush has a charge of –1.4 × 10-8 coulombs. if the distance between the fur and brush is roughly 5.0 × 10-1 meters, what is the approximate magnitude of the force between them? (k = 9.0 × 109 newton·meters2/coulomb2)

The equation in Coulomb's law is F ={k*q1*q2}/r^2 where F is the force between charges, k is a constant, q1 is the charge of the first particle, q2 is the charge of the second particle and r is the distance between the two particle charges. 

Substituting to the equation:
F =k*q1*q2/r^2 = { 9x10^{9} * 8x 10^{-9} *-1.4x10^{-8} }/ ((5x10^-1)^2)
= -4.032x10^-6 Newtons 

☁️ Answer ☁️

Inside each circuit breaker is a spring hooked over a small piece of solder (a melt-able fusible alloy). Each breaker is connected to an electrical wire that runs through your house. The electricity that flows through your house runs through the solder.

Hope it helps.

Have a nice day noona/hyung!~ ￣▽￣❤️