Physics help part 2

[hrtbrk1 5,000+ posts]

yeah i **** at this subject.

A heat engine running backward is called a refrigerator if its purpose is to extract heat from a cold reservoir. The same engine running backward is called a heat pump if its purpose is to exhaust warm air into the hot reservoir. Heat pumps are widely used for home heating. You can think of a heat pump as a refrigerator that is cooling the already cold outdoors and, with its exhaust heat QH, warming the indoors. Perhaps this seems a little silly, but consider the following. Electricity can be directly used to heat a home by passing an electric current through a heating coil. This is a direct, 100% conversion of work to heat. That is, 18.0 kW of electric power (generated by doing work at the rate 18.0 kJ/s at the power plant) produces heat energy inside the home at a rate of 18.0 kJ/s. Suppose that the neighbor's home has a heat pump with a coefficient of performance of 3.00, a realistic value.

A.)How much electric power (in kW) does the heat pump use to deliver 18.0 kJ/s of heat energy to the house?

B.)An average price for electricity is about 40MJ per dollar. A furnace or heat pump will run typically 100 hours per month during the winter. What does one month's heating cost in the home with a 18.0 kW electric heater?

C.)What does one month's heating cost in the home of the neighbor who uses an equivalent heat pump?

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[hrtbrk1 5,000+ posts]

anyone?

 

[edzy 10+ year member]

http://www.builditsolar.com/References/Calculators/HeatLoss/HeatLoss.htm

 

[hrtbrk1 5,000+ posts]

that don't help too much...

 

[blazeplacid 10+ year member]

why would you come here for physics help??

 

[hrtbrk1 5,000+ posts]

why not...lol they helped me before

 

[ThatChevyGuy 5,000+ posts]

You think this is hard?

LOL

 

[Scoobydoo 5,000+ posts]

chocolate babies

 

[hrtbrk1 5,000+ posts]

got it //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[tinmanchris217 10+ year member]

Do you own homework. Many of us have done this stuff, but you gotta put in your time.

I studied my arse off for Thermodynamics at LSU. We had class at 8:30 am, 5 days a week, and the teacher got special permission to give us a 6 hour final. Misery.

Check this link for help

 

[hrtbrk1 5,000+ posts]

Do you own homework. Many of us have done this stuff, but you gotta put in your time.
I studied my arse off for Thermodynamics at LSU. We had class at 8:30 am, 5 days a week, and the teacher got special permission to give us a 6 hour final. Misery.

Check this link for help

i take thermo too! just physics teacher aint that great at explaining things and uses different methodology and crap...but i got the answer thanks

 

[hrtbrk1 5,000+ posts]

oh and thanks fo4r the link