as you can see the numbers get rather large so we use the hour rather than second so there are 360 kJ = 1kWh
No. 1 J = 1 Ws So 1kWs = 1000 J and 1 kWh = 3,600 kJ or 3.6 MJ.
the unit is rather crazy as energy has no time
Well clearly it does. The Joule
is the SI derived unit for energy and it
is 1 Watt-second. Or 1 kg⋅m²⋅sˉ² if you prefer, but there's time again.
so the time in the watts cancels out the hours
No. kWh is a quantity of energy. It's 3.6MJ. If you transfer 1 kW for 1 hour you have transferred 1 kWh. If you transfer 500W for 2 hours you have transferred 1kWh.
It's like saying I have two eyes per hour and 48 eyes per day / hours.
No, it's like saying you have 2 eyes, and if you use them for 1 hour you have used 2 eye hours. Which could conceivably be a unit which makes sense. If we had humanoid robots which recorded things, then you could say that the latest Nexus 5 GTi has a recording capacity of 200 eye hours. Shut down one eye and it could record for 200 hours.
And just like (price-breaks and network capacity aside) the way that if you transfer 1,000 kWh from your electricity supplier they don't care if you use 1MW for 1 hour or 114W for a year, the bill is still £140, the Nexus 5 GTi could fill its memory in 4 days and 4 hours with both eyes running all the time or in 200 days with 1 eye working for 1 hour per day.
Energy is timeless if you lift 550 pounds one foot up it has energy only when you release that energy and allow it to return
No, it has (an extra 550 foot-pounds of) potential energy. The reason that it has that is because the 550 lb is related to gravitation acceleration, which has a time dimension. Were you to lift the same object up by 1 foot on the Moon you would have added 91 ft-lb, on Jupiter it would be 1300.
in say one second does it have power in that case one horse power.
Power is not the same as energy. Energy is the
amount of work that can be performed by a force, power is the
rate at which the work is performed.
A Watt is a unit of power. A Joule, or 1 Watt-second is a unit of energy.
A 10hp car weighing X and a 1000hp car weighing X can both get from A to B, but the 1000hp one, being
more powerful, will do it in
less time. Assuming 100% efficient engines they would both consume the same amount of fuel.
So look on the side of a freezer it says something like 250 kWh/annum clearly the hour and annum cancel them selves out so there is no time.
No they don't and yes there is.
It will use 250kWh of energy every year. It's a 28.52W load.
So it should say something like 90000 kJ.
In what time? It is a 28.52W load, so for it to use a given number of kJ it would have to run for a given amount of time. In this case, to use 90000 kJ that would be about 36.5 days
The label could accurately say 0.9GJ/annum, but since people are billed in watt-hours and not Joules that wouldn't be very helpful.
No there aren't. 1 N = 1 kg·m/s². On Earth a mass of 1kg exerts a force of about 9.8 N (Earth's gravitational acceleration being about 9.8 m/s²). On Earth 980 kg would exert a force of about 9.6 kN. On Jupiter it would be about 22.7 kN.
The only way you could sort-of-reasonably say "there are X g in a Newton" (as a sort of sloppy shorthand for saying "a mass of X g exerts a force of 1 N) is to recognise that you have to have a particular gravity in mind. On Earth, BTW, there's about 102g "in" 1 N.
1 N = 1000 g·m/s². 1000/9.8 = 102
it would seem the computer world is returning to imperial with 32 pound in a slug etc.
A slug is an Imperial unit of mass. On Earth it weighs about 32.2lb (on Earth, gravitational acceleration is about 32.2 ft/s²). It's nothing to do with computing.
Any wonder kids to day get confused as to what to call things?