Answer to Question #175879 in Physics for J B

Question

A dogs fur is combed and the gains a charge of 8 uC. Find the electric force between the fur and the comb when they are 2.0 cm apart. Include if they are attractive or repulsive.

Answer 1

Since both the dogs fur and the comb were initially neutral, then charge obtain by the comb will be -8uC according to the charge conservation law. Thus, the force between them will be attractive (the charges have different sign).

The exact value of the force can not be calculated wihout knowing the geometry of the comb and the dogs fur. Obviously the distance of 2cm is very small to consider these charges to be a point ones. Thus, the direct application of the Coulomb's law is not possible.

Answer. The force is attractive.