Two fixed navigation beacons mark the approach lane to a star. the beacons are in line with the star and are 40 mm apart. a spaceship approaches the star with a relative velocity of 0.30 c and passes the beacons. the passage of the ship between the beacons is timed by observers on the beacons. the time interval of the passage is closest to:

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?

Need asap ‼️ 20 pts which gravitational force field diagram is drawn correctly? (answers in pictures below)

What effects result when there is an impact between earth and an asteroid? check all that apply. a. massive flooding. b. extinction of many life forms. c.major earthquakes change in average global temperature. d. giant dust cloud