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)

One soccer player (a) is moving at 4 km/h when she kicks the ball while another soccer player (b) is moving at 8 km/h. what statement accurately compares their kinetic energy if they have the same mass? a) both soccer players have the same kinetic energy. b) player b has twice the kinetic energy of player a. c) player b has four times the kinetic energy of player a. d) their kinetic energy can't be compared without knowing their mass.