100 m W can 7 Km

according http://uk.youtube.com/watch?v=xNFg8l5tjDI

I draw conclusion from the movie at 0.22 second from the above movie


1000 m W = 1 W

1 W can reach 7KM * 10

5 W = 7KM * 10 * 5

= 350 KM the signal still cannot reach the AO 51 satellite which is
850 Km away from the earth.


to reach AO 51 the power required at least 12.5 W

7KM * 10 * 12.5
=875 KM


is my calculation correct?