I would go with both A and B. But you might want to wait for a better answer cause I'm not too sure
Answer:
7572 m/s
Explanation:
The force between two masses separated by a distance r is given as:

Where F is the attractive force between 2 masses, m1 and m2, r is the distance between the centres of the masses and G is the universal gravitation constant, which is 
The mass of the earth (
) is far greater than the mass of the sputnik (
). Therefore
. The mass of the sputnik is neglected, therefore:

But F is actually centripetal acceleration, a = v²/r

The answer is: [C]: "protons and electrons" .
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Answer:
Because the velocity v (As a Vector ) is going opposite direction ( -X axis ) .