At an airport, delta needs to check in two flights that leave at the same time. for each of the two flights, 160 passengers will arrive randomly over the next two hours. there are 3 employees assigned to each flight and each employee can a passenger on average in 2 minutes (due to online and kiosk check-ins – this used to be 10 minutes), with a standard deviation of 2 minutes. how much does the average waiting time decrease when these two flights are pooled such that all passengers can go to all six employees? (first solve for the wait time assuming two "unpooled" systems, each of which has an arrival rate of 80 per hour. then solve for the wait time assuming a pooled system, with m=6. then find the difference in wait time.)

Aregion of space in which a measurable gravitational force is indicated by the force exerted on a test mass is called

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?

The necleus of an atom is made up of what subatomic particles?