4) According to the ancient Greeks, the Earth was the center ofthe universe and the sun, moon, stars, and planets all went aroundthe Earth. In the 1543 Copernicus proposed the heliocentric theoryof the universe in which the Earth was just another planet orbitingthe Sun and only the moon orbited the Earth.
a) What is the speed at which the Moon goes around the Earth?
b) How does the Moon's orbital acceleration compare to theacceleration of objects near the surface of the Earth?
c) What is the magnitude of the force that the Earth's gravityexerts on the Moon to keep it in orbit?
d) According to Newton's third law, all forces occur in pairs. Whatis the reaction to the Earth's gravity on the moon? Explain.