An electric-dipole antenna is located on the roof of a 201-m-high building and i

Question

An electric-dipole antenna is located on the roof of a 201-m-high building and is oriented vertically. An observer on the ground measures the intensity of the radiation from the antenna and finds 8.45 mW/m2. This observer is 1.09 km away from the antenna. A second observer hovers in a blimp at an altitude of 575 m and measures the radiation intensity from the antenna when she is 1.43 km from the antenna. What intensity, in milliwatts per square meter, does she measure?

Note: I have already referenced other similar questions that have been posted and answered, but those methods are not giving me the correct answer. So please do not just copy what they have already contributed. I will not award you points.

Explanation / Answer

here,

distance of the observer 1 , d1 = 1.09 km

d1 = 1090 m

intensity at 1 , I1 = 8.41 mW/m^2

I1 = 0.00841 W/m^2

let the power of antenna be P

I1 = P/d^2

0.00841 = P /(1090^2)

P = 9991.92 w

distance of seccond observer , d2 = 1.43 km

d2 = 1430 m

I2 = P/(1430^2)

I2 = 9991.92 /(1430^2)

I2 = 4.89 mW/m^2

the intensity she measures is 4.89 mW/m^2

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.