Answer:
it’s 9!
Step-by-step explanation:
I=PRT/100
40=(500XRX2)/100
R=(40X100)/500X2
R=4000/1000
R=4 percent/annum
ionosphere
In radio communication, skywave or skip refers to the propagation of radio waves reflected or refracted back toward Earth from the ionosphere, an electrically charged layer of the upper atmosphere
