Question

The answer isn't 2.08 or 2.58

1 Review I Constants Public Radio station KXPR-FM in Sacramento broadcasts at 88.9 MHz. The radio waves pass between two tall skyscrapers that are 15.0 m apart along their closest walls. At what horizontal angles, relative to the original direction of the waves, will a distant antenna not receive any signal from this station? Enter your answers in ascending order separated by commas. Enter only positive angles. Express your answers in dergees. 8 = 13.0-26.7,42.4,64.1 Submit Previous Answers Correct Part B If the maximum intensity is 3.80 W/m" at the antenna, what is the intensity at +6.00 from the center of the central maximum at the distant antenna? Express your answer in watts per square meter. IVO AO ? I = 2.58 W/m

Answer 1

a) Wavelength of the wave is, 3 x108 m/s 2= 88.9x10 Hz = 3.375 m Horizontal angle is, For m=1 m2 O= sin (1)(3.375 = sin 15 +13° For m=2 m2 O = sin a = sin (2)(3.375 15 = +26.7° For m=3 m2 O=sin a (3)(3.375 ) = sin 15 = +42.50 For m=4 m2 O=sin? a (4)(3.375 = sin 15 = 164.2°

b) Intensity is, sin B 2 I=1. B 2 sin = 1, = πα sin θ 2 na sin e 2 sin T (15 m)sin (6.0) 3.375 (3.80 W/m A (15 m) sin(6.0) 3.375 = (3.80 W/m² sin (1.459 rad) 1.459 rad = (3.80 W/m²) 0.9937 rad 1.459 rad = 1.76 W/m2