El courses cffered Concarderspeutic Exercise tm Cours Pus to Polon Use Radar Gun
ID: 778579 • Letter: E
Question
El courses cffered Concarderspeutic Exercise tm Cours Pus to Polon Use Radar Guns And .. Chapter 24, Problem 64 The figure shows the popular dish antenna that receives digital TV signals from a satellite. The average intensity of the electromagnetic wave that carries a particular TV program is s-7.50 x10/m2, and the circular aperture of the antenna has radius of r = 13.3 cm. (a) Determine the electromagnetic energy delivered to the dish during a one-hour program (b) what is the average energy density of the electromagnetic wave? Area A TV signal (a) Number (b) Number Click if you would like to Show Work for this question: Units Question Attempts: 0 of 5 usedSAVE FOR LATER SUBMIT ANSWERExplanation / Answer
a) t = 1 hr = 3600 s, r = 13.3 cm = 0.133 m
A = pi (0.1332) = 0.0555 m2, I = 7.50 * 10-14
Energy delivered = I A t = 7.50 * 10-14 * 0.0555 * 3600
= 1.5 * 10-11 J
b) Average energy density = I / c
= ( 7.50 * 10-14) / (3 * 10^8)
= 2.5 * 10-22