The message is the information being communicated from one place to another.
It used to be called the "intelligence". But as time went on, it became
harder to ignore the obvious fact that that was going too far, and the
label was changed to the more IQ-neutral "message".
Answer:

Explanation:
As we know that the satellite revolves around the planet then the centripetal force for the satellite is due to gravitational attraction force of the planet
So here we will have

here we have


here we have

now we can find time period as




Now the density is given as



Note that
1 J = 0.239 cal
By definition,
Work = Force x Distance
Therefore work done is
W = (1 N)*(2000 m) = 2000 J
In calories,
W = (2000 J)*(0.239 cal/J) = 478 cal
Answer: 478 calories