What two factors are responsible for the delay between the time we send a radio message to astronauts on the moon and when they receive it?

Idon’t quite understand this problem

The experiment done in lab is repeated, using a ball that has unknown mass m. you plot your data in the form of f 2 versus m/l, with f in rev/s, m in kg, and l in m. your data falls close to a straight line that has slope 3.19 m/(kg · s2). use g = 9.80 m/s2 and calculate the mass m of the ball.

Holes drilled several kilometers into earth’s crust provide direct evidence about earth’s interior in the form of