Given:
distance of observer from the sound source, [tex]s=70~m[/tex]
distance between the source of image information sender and the receiver, [tex]d=45~miles=72420.48~m[/tex]
Assumptions:
speed of sound, [tex]v=343~m/s[/tex]
speed of the image information being sent, [tex]c=3\times 10^8~m/s[/tex] (we assume it to be nearly the speed of light in vacuum)
Solution:
Time taken by the sound to reach the observer:
[tex]time=\frac{distance}{speed}[/tex]
[tex]time=70\div 343[/tex]
[tex]time \approx 0.2~s[/tex]
Time taken by the image to reach the destination:
[tex]time=\frac{72420.48}{3\times 10^8}[/tex]
[tex]time=2.4\times 10^{-4}~s[/tex]