If a signal has a strength of 100 mW at 10 meters,how strong will it be at 40 meters?
A) about 0.5 mW
B) about 5 mW
C) about 25 mW
D) about 6 mW

Question

Quizplus · Accepted Answer

The signal strength follows an inverse square law, which means that the signal strength will decrease with the square of the distance. Therefore, the signal strength at 40 meters can be calculated using the formula:

(signal strength at 40 meters) = (signal strength at 10 meters) x (10/40)^2

(signal strength at 40 meters) = 100 mW x (10/40)^2

(signal strength at 40 meters) = 100 mW x 0.0625

(signal strength at 40 meters) = 6.25 mW

Rounding this to the nearest whole number gives approximately 6 mW, which is answer choice D.

If a Signal Has a Strength of 100 MW at 10