The average Earth–Sun distance is 1.00 astronomical unit (AU). At how many AUs from the Sun is the intensity of sunlight 1/49 the intensity at the Earth?

Write equations for both the electric and magnetic fields for an electromagnetic wave in the red part of the visible spectrum that has a wavelength of 714 nm and a peak electric field magnitude of 2.0 V/m. (Use the following as necessary: t and x. Assume that E is in volts per meter, B is in teslas, t is in seconds, and x is in meters. Do not include units in your answer. Assume that E = 0 and B = 0 when x = 0 and t = 0.) E(x, t) = B(x, t) =

The electric field of an EM wave in vacuum is given by En = 30 cos (27 × 10°t + 3); Ey = 0; Ez = 0; where E is in volts/meter, t in seconds, and x in meters. Determine the frequency f, the wavelength A, the direction of propagation of the wave, the direction and amplitude of the magnetic field.

a solar panel is a square 0.5m on a side and absorbs all the light that hits it. It the panel has a mass of 3 kg. what intensity of light would be necessary to hold it up against the force of gravity (its own weight)? how much bigger is this than the solar constant (1400 W/m^2)?

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Compute an order-of-magnitude estimate for the frequency of an electromagnetic wave with wavelength equal to (a) your height and (b) the thickness of a sheet of paper. How is each wave classified on the electromagnetic spectrum?

What is the frequency of a microwave in free space whose wavelength is 1.65 cm?

an AM station operating at a frequency of 750 kHz. what is m?

An anstonomer on a planet orbiting the star Deneb wants to differentiate the reflected light by Earth from the light of the Sun. First, consider the area of Earths disk which reflects the Sun's intercepted light. Second, consider the surface area of a sphere with the same radius as Earths orbit around the Sun. Take the ratio of these two areas. Assume the Earths radius is 6400.0 km and is 1.3 x108 km from the Sun.

In a particular city, electrical energy costs $0.13 per kilowatt-hour. (Round your answers, in dollars, to at least two decimal places.)   (a) How much does it cost to operate an old-style incandescent 60.0-W light bulb continuously for 24 hours? $ ??? (b) A modern LED light bulb that emits as much visible light as a 60.0-W incandescent only draws 8.50 W of power. How much does it cost to operate this bulb for 24 hours? $ ??? (c) A particular electric oven requires a potential difference of 220 V and draws 20.0 A of current when operating. How much does it cost to operate the oven for 4.30 hours? $ ???