The position vector x for an electron moving with velocity much less than c in a plane monochromatic wave epsilon e_0 cos(omega t - kz) is determined by the equation of motion md^2 x/dt^2 = e epsilon e_0 cis (omega t - kz). show that the refractive index of an electron gas is given by eq. (3.14.13). assume that in the ionosphere the refractive index for 100-mhz radio waves is 0.90 and that the free electrons make the greatest contribution to the index. estimate the number density of electrons. why is the contribution of positively charged ions to the refractive index much smaller? choose an am and an fm radio station in your area and compare their frequencies to the plasma frequency of the ionosphere.

Determine the maximum r-value of the polar equation r =3+3 cos 0

Which of these statements is true? a. quarks pair with leptons to form protons and neutrons. b. quarks pair with bosons to form photons. c. quarks pair with photons to form protons and neutrons. d. quarks pair with other quarks to form protons and neutrons. e. quarks pair with electrons to form protons.

While studying chemical reactions and conservation of matter, sarah's class conducted a variety of experiments. sarah and her lab partner found the mass of a wax candle and placed the candle in a flask. the students lit the candle and let it burn to completion. all that was left was wax and charred candle wick. per their teacher's instructions, the students found the mass of the products. their data can be seen in the data table. formulate a hypothesis the students could test to explain why the experiment did not support the law of conservation of matter. a) the students could repeat the experiment using different candles; there might have been a flaw in the candle. b) the experiment should be repeatable. the students should run several trials and then take an average of the after mass in each trial. c) the students should have someone in the class check their measurement skills as they repeat the experiment. they may have made an error using the balance. d) the students should burn the candle in a container that has some type of lid so that any gas that is a product of the reaction can be contained and massed. submit