Aplane wave is incident on a boundary that separates two regions with int impedances 뀌-200 ω and 72-400ωκη0wing that the incident wave's electric nsi intensity has a magnitude of e, to 120 v/m, calculate the following quantities their names and units: intrinsic and give problem 4 (25 pts) a 2.2 ghz uniform plane wave is normally incident onto a freshwater lake (ε,-78, 4.1) determine the fraction of the incident power that is reflected. 4.2) determine the fraction of the incident power that is transmitted. 4.3) determine the amplitude of the electric field that is transmitted into the lake.

Tall pacific coast redwood trees can reach heights of about 100 m. if air drag is negligibly small, how fast is a sequola cone moving when it reaches the ground f it dropped from the top of a 100 m tree?

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?

Abike rider starts from rest and accelerates 28.0 meters down a slope in 5.00 seconds. what is her acceleration? select one: a. 3.21 m/sec2 b. 1.75 m/sec2 c. 9.80 m/sec2 d. 2.24 m/sec2