Night hunting animals have more rod cells in their retinas which allows them to see better in the dark.
The increased thickness of the fox's fur allows the fox to warmer in cold temperatures, while the shorter fur does the opposite.
Power = (voltage) x (current)
500 W = (120 v) x (current)
Current = (500 w) / (120 v) = 4-1/6 amperes .
Power and current are both rates.
Power is the rate of using energy ... joules per second.
Current is the rate of flowing charge ... coulombs per second.
Neither quantity depends on how long you keep it up.
They're both going on continuously while the vacuum is running.
