IESSAGE MY INSTRUCTOR FULL SCREEN PRINTER VERSION BACK NEXT Chapter 24, Problem
ID: 1446162 • Letter: I
Question
IESSAGE MY INSTRUCTOR FULL SCREEN PRINTER VERSION BACK NEXT 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 7.30 x 10-14 W/m2, and the circular aperture of the antenna has radius of r = 15.3 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 TV signal Units (a) Number (b) Number Click if you would like to Show Work for this question: Open Show Work Units Question Attempts: 0 of 5 used SAVE FOR LATER SUBMIT ANSWERExplanation / Answer
a) we know, Inetnsity = Power/Area
==> POwer = Intensity*Area
Energy delivered = Power*time
= Intensity*Area*time
= 7.3*10^-14*pi*0.153^2*60*60
= 1.93*10^-11 J
b) Average energy density = E/volume
= E/(L*A)
= E/(c*t*A)
= 1.93*10^-11/(3*10^8*60*60*pi*0.153^2)
= 2.43*10^-22 J/m^3