Question

suppose an isolated tower is 30 meters high. according to umans estimate, that means a leader that comes within 60 meters will be intercepted by an upward - going leader from the object. an area with a radius of 60 meters is roughly 11,310 square meters. if the ground - strike frequency where the tower is located is 5 per square km per year, what is frequency with which the tower will likely be struck?
a. $5.65\times10^{-2}$ flashes per year
b. $2.83\times10^{-2}$ flashes per year
c. 20 flashes per year
d. 20,000 flashes per year
\bigcirc a
\bigcirc b
\bigcirc c
\bigcirc d

Explanation:

Step1: Convert area to square kilometers

The area of the region around the tower is 11,310 square meters. Since 1 square km = \(10^6\) square meters, we convert the area: \(A=\frac{11310}{10^6}\) square km.

Step2: Calculate the strike frequency

The ground - strike frequency is 5 per square km per year. So the strike frequency for the tower's area is \(f = 5\times A\). Substitute \(A=\frac{11310}{10^6}\) into the formula: \(f = 5\times\frac{11310}{10^6}=\frac{56550}{10^6}=5.655\times 10^{-2}\approx5.65\times 10^{-2}\) flashes per year.

Answer:

a. \(5.65\times 10^{-2}\) flashes per year