his is an artist's model of the solar system. The scale bar in the drawing represents AU s. One AU is the distance rom the Sun to the Earth, which is about 93 million miles or 150 million kilometers. Is this an accurate scale model? Explain A) No. If Earth is 1 AU away from the Sun, Neptune should be about 30 AU'S away. It is not B) Yes, it is an accurate scale model showing the relative distances of each planet from the Sun. C Yes the drawing is to scale. The artist shows how the diameters compare as well as the distances from the Sun in AU's. Neither the distances from the Sun or the size of the planets are drawn to scale. Both are too small according to actual distances and diameters,​

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 energy released by a nuclear fusion reaction is produced when

Exercise 2. find the wavelength of a photon emitted when an electron jumps from the n = 3 energy level down to the n = 2 energy level. where is this photon in the electromagnetic spectrum?