There are 746 watts per HP, its just something you have to remember.
There is none. Electricity and miles per hour do not relate.
46.6 watts an hour.
Watts is voltage (in volts) x current (in amps)
40 Joules, I think, as the formula for Watts is Joules/Second = Joules per second 40 Watts should equal 40 Joules per one second...
The formula for watts is, Watts = Amps x Volts.
Conversion from watts to horsepower use, 746 watts = 1 HP.
Watts are watts, the conversion is already done in the way AC voltage is measured.
1 HORSE POWER = 746 Watts
The formula you are looking for is; Watts = Amps x Volts. So in your case VA is Watts
Amps * Watts = Volts OR, from high school algebra Amps = Volts/Watts
746 watts per horsepower