A possible means of space flight is to place a perfectly reflecting aluminized sheet into orbit around the Earth and then use the light from the Sun to push this "solar sail. Suppose a sal of ares A 6.30 x 10 m² and mass m - 7,000 kg is placed in orbit facing the Sun. Ignore all gravitational effects and assume a solar intensity of 1,370 W/m² (a) What force (in N) is exerted on the sail? (Enter the magnitude) (b) What is the sair's acceleration? (Enter the magnitude in um/s².) m/s2 (c) Assuming the acceleration calculated in part (b) remains constant, find the time interval (in days) required for the sail to reach the Moon, 3.84 x 10 m away, starting from rest at the Earth days (d) What If? If the solar sail were initially in Earth orbit at an altitude of 400 km, show that a sail of this mass density could not escape Earth's gravitational pull regardless of size. (Calculate the magnitude of the gravitational field in m/s².) m/s² (e) What would the mass density (in kg/m²) of the solar sail have to be for the solar sall to attain the same initial acceleration as that in part (b)? kg/m²

(b) The earth has a radius of R = 6.4 x 106 m. It orbits the sun in a nearly circular orbit at an average distance of r = 1.5x 10¹1 m. The solar intensity at the upper atmosphere is 1367 W/m². How much energy does the sun radiate per second?

An old-fashioned incandescent bulb (100 W) has a tungsten filament inside which glows at a steady temperature of 24000C and radiates electromagnetic waves (part heat, part light). What is the surface area of the filament? Assume emissivity of tungsten is 0.35. a) 9.9*10-4 m2                                     b) 9.9*10-5 m2                                c) 1.5*10-4 m2

At the top of Earth’s atmosphere, sunlight has an averageintensity of 1360 W>m2. If the average distance from Earth to theSun is 1.50 * 1011 m, at what rate does the Sun radiate energy?

Problem: Radiation Related   The energy flux associated with solar radiation incident on the outer surface of the earth's atmosphere has been accurately measured and is known to be 1,368 W/m^2. The diameters of the sun and earth are 1.39 X 10^9 and 1.27 x 10^7 m, respectively, and the distance between the sun and the earth is 1.5 × 10^11 m.   (a) What is the emissive power of the sun? (b) Approximating the sun's surface as black, what is its temperature? (c) At what wavelength is the spectral emissive power of the sun a maximum? (d) Assuming the earth's surface to be black and the sun to be the only source of energy for the earth, estimate the earth's surface temperature.

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? $ ???

Betelgeuse, a red-giant star in the constellation Orion, has a peak in its radiation at a frequency of 3.09 X 10^14 Hz. What is the surface temperature of Betelgeuse?

(a) Calculate the rate in watts at which heat transfer through radiation occurs (almost entirely in the infrared) from 1.0 m2 of the Earth’s surface at night. Assume the emissivity is 0.90, the temperature of the Earth is 15ºC , and that of outer space is 2.7 K. (b) Compare the intensity of this radiation with that coming to the Earth from the Sun during the day, which averages about 800 W/m2, only half of which is absorbed. (c) What is the maximum magnetic field strength in the outgoing radiation, assuming it is a continuous wave?

Let's try a few more examples that relate power and energy. A certain high-efficiency LED light bulb has a power output of 9.20 W. That is, 9.20 J of electric energy is converted to electromagnetic (light) energy and radiated away every second. How much energy is output by the lightbulb if it is left on for a total time of 7.50 hours? In this case, we're relating power to energy change, so we simply use the relationship E t P = Here, instead of work W, we use in the equation E, which is the amount of energy output or converted in the amount of time t. From this, what do we find the total energy output in joules to be? 33120 X x Solve the above equation for the energy E in terms of power P and time t. Remember that 1 W = 1 J/s, so to find the energy in joules, convert the time to seconds first. There are 60 minutes in one hour and 60 seconds in one minute. J

To maximize the radiation pressure on the sails of a spacecraft using solar sailing, should the sheets be (a) very black to absorb as much sunlight as possible or (b) very shiny to reflect as much sunlight as possible?