Answer:
The period of a wave is the time for a particle on a medium to make one complete vibrational cycle. Period, being a time, is measured in units of time such as seconds, hours, days or years. The period of orbit for the Earth around the Sun is approximately 365 days; it takes 365 days for the Earth to complete a cycle.
My inference is that the water molecules are moving up and down. I don't know for sure but i'm usually correct.
The purpose of the brush is supposed to be to lessen the amount of damage or wear placed upon the motor. I hope this helps with your answer choices since you did not post any.
