a student combed his hair. then he observed what happened to the water when he put the comb near the faucet.

The student noticed that the water stream from the faucet was attracted to the comb, causing it to bend towards the comb. This is due to the static charge created by combing the hair, which results in the comb becoming negatively charged and attracting the positively charged water molecules. This is a simple demonstration of static electricity at work.