Question

a person brushes the hair on a cat with a metal comb. the strands of hair begin to stick up in the air and move away from each other. which type of force causes the hair to respond in this way, and why? a action force; the strands of hair exert a force on the comb during brushing, pushing the hair in the opposite direction of the comb. b electric force; the strands of hair become positively charged when negative particles from the hair move to the comb during brushing. c gravitational force; the strands of hair become lighter after being brushed and are influenced less by gravity. d magnetic force; the strands of hair and comb have opposite poles caused by the metal in the comb.

Explanation:

When a metal comb is used to brush a cat's hair, electrons (negative particles) transfer from the hair to the comb. This makes the hair positively charged. Like - charged objects repel each other due to the electric force.

• Option A: Action - force is about Newton's third - law (action - reaction pairs). But this situation is not about the force of hair on comb in the opposite direction of comb's motion.
• Option C: Gravitational force depends on mass. Brushing does not make the hair lighter in terms of mass.
• Option D: There is no indication of magnetic poles being created in the hair or comb.

Answer:

B. Electric force; the strands of hair become positively charged when negative particles from the hair move to the comb during brushing.