The maximum fequency for reflection of sky waves from a certain layer bof the ionosphere is found to be `f_(max) =9(N_(max))^(1//2)`, Where N _max is the maximum electron density at that layer of the ionosphere.On a certain day it is observed that signals of frequencies higher than 5 MHz are not received by reflection from the `F_(1)` layer of the ionosphere while signals of frequencies higher than 8 MHz are not received by reflection from the `F_(2)` layer of the ionosphere. Estimate the maximum electron densities of the `F_(1)` and `F_(2)` layers on that day.

Explanation

The maximum frequency for reflection of sky waves
`f_("max")=9(N_("max"))^(1//2)`
where, `N_("max")` is a maximum electron density.
For `F_(1)` layer, `f_("max") = 5 MHz`
So, `5xx10^(6) = 9 (N_("max"))^(1//2)`
Maximum electron density
`N_("max")=((5)/(9)xx10^(6))^(2)=3.086 xx 10^(11)//m^(3)`
For `F_(2)` layer, `f_("max")=8MHz`
So, `8xx10^(6)=9(N_("max"))^(1//2)`
Maximum electron density `N_("max")=((8xx10^(6))/(9))^(2)=7.9 xx 10^(11)//m^(3)`