can someone help me out and explain to me this? it's problem 68. I have Mass of Earth, Earth-moon distance, Earth Speed, and Radius of Earth. how does one solve?

I'm having some difficulty seeing the diagram clearly.but the question says there's a net inward force on the object.so we know right away,  from newton's 2nd law of motion, thatthat baby is accelerating.  it doesn't even matter which way thenet force is pointing.  if there's any net force, then either theobject's speed or else its direction must be changing.

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Ithink the answer for this is: an electromagnet is a magnet  with a soft metal core.