If two energuide says 92kWh and 127kWh, which one has lower cost of operation and why??
How to determine appliances that use lots of energy and that uses little energy? (like heat, brightness, etc.)
What is the unit of energy?
I thought it's joules, but I have a question asking me to choose one from W, kW, kW/h, and kWh.
I have assignment that is for marks.
Could you please help??
2007-05-18 02:44:48 · 5 answers · asked by Sayaka 1 in Science & Mathematics ➔ Physics
Energy is measured in Jules
92 kWh is obviously less energy than 127 kWh
but at what efficiency?
efficiency = (useful power)/ (total power consumed)
also
1 Joule equal to a work done by applying a force of 1 Newton displacing an object by 1 meter
1 Joule equal to 1 Watt of power supplied for 1 second.
So 1 kWh = 1000 x 1 x 3600= 3,600,000 joules
Does that help?
Also
Power = Voltage x current
So if a 120Volt appliance uses 10 Amps of current it consumes 1200 watts of power or 1.2 kW
2007-05-18 02:50:40 · answer #1 · answered by Edward 7 · 1⤊ 0⤋
92kwh has lower cost.....coz its consuming 92000W in 1 hour while the other 127000W
Actually it's very difficult to determine its power by calculation the energy released etc.... coz u cant calculate the exact specific amount of energy released(actually u can...but its difficult)....more over there are many types of losses u have to keep in mind.
W/KW are all units of energy......they can be converted to joules.....joules being a much smaller unit
kW/h is some wat like j/h....i.e joules per unit time.......energy consumed/hour by the appliance
2007-05-18 10:00:00 · answer #2 · answered by Anonymous · 0⤊ 0⤋
Using energy systems we are using now, there is a better engineering way to reduce the over all way energy is conducted in these systems. ( The overall KWh would be reduced 30% a year Nationally, based on devices and circuit flow charting changes....
2007-05-18 10:24:22 · answer #3 · answered by Anonymous · 0⤊ 0⤋
92 uses less energy (cheaper).
Heat and compressors use energy. Fluorescent bulbs are more efficient than incandescent, and LED bulbs more yet. 746W = 1 horsepower. Less amperage is less energy at same voltage. voltsxamps=watts. Irons, toasters, air conditioners, water heaters, electric stoves, and microwave ovens use lots of power
joules is work. kWh is too (Kilowatt-hours=1000watts for 1 hour)
2007-05-18 09:55:44 · answer #4 · answered by Anonymous · 0⤊ 0⤋
DO YOUR HOME WORK YOUR SELF
2007-05-18 09:48:08 · answer #5 · answered by tiki 1 · 1⤊ 0⤋