A2.4-m high 200-m2 house is maintained at 22â°c by an air-conditioning system whose cop, is 3.2. it is estimated that the kitchen, bath, and other ventilating fans of the house discharge a houseful of conditioned air once every hour. if the average outdoor temperature is 32â°c, the density of air is 1.20 kg/m3, and the unit cost of electricity is $0.10/kwh, the amount of money "vented out" by the fans in 10 hours is
(a) $0.50
(b) $1.60
(c) $5.00
(d) $11.00
(e) $16.00

Alfred pushes on a heavy box, but cannot move it. the box has a lot of inertia motion friction gravity

Aheat 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, 19.0 \rm kw of electric power (generated by doing work at the rate 19.0 kj/s at the power plant) produces heat energy inside the home at a rate of 19.0 kj/s. suppose that the neighbor's home has a heat pump with a coefficient of performance of 4.00, a realistic value. note: with a refrigerator, "what you get" is heat removed. but with a heat pump, "what you get" is heat delivered. so the coefficient of performance of a heat pump is k=qh/win. an average price for electricity is about 40 mj per dollar. a furnace or heat pump will run typically 200 hours per month during the winter. what does one month's heating cost in the home with a 16.0 kw electric heater? what does one month's heating cost in the home of a neighbor who uses a heat pump to provide the same amount of heating?

What is the rate of change in a objects position?