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Unformatted text preview: Solve: (a) The wave is propagating in the direction. (b) direction (c) direction (d) direction 23.15. Set Up: At a distance r from the station the power output of the antenna is spread over a spherical surface of area where I is the intensity at distance r and P is the power output of the antenna. Solve: (a) (b) (c) so so and Reflect: The intensity decreases as and the electric field decreases as as the distance r from the source increases. 23.16. Set Up: The intensity is related to the maximum electric field by where The average energy density is related to the intensity I by Solve: (a) (b) (c) 23.17. Set Up: The surface area of a sphere of radius r is with Solve: (a) (b) Reflect: At the surface of the bulb the power radiated by the filament is spread over the surface of the bulb. Our cal- culation approximates the filament as a point source that radiates uniformly in all directions. 23.18. Set Up: Intensity is average power per unit area and power is energy per unit time. If the energy is absorbedIntensity is average power per unit area and power is energy per unit time....
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This note was uploaded on 03/06/2009 for the course PHYS 114 taught by Professor Shoberg during the Spring '07 term at Pittsburg State Uiversity.
- Spring '07