"The Moon (m=7.35x10^22 kg) is a natural satellite of Earth (m=5.98x10^24 kg), which has an average distance from Earth's centre of 3.85x10^8 m.

What is the Moon's kinetic energy and speed while in orbit around Earth?"

I've solved for the Moon's kinetic energy (found it to be 3.82x10^28 J) which got the same answer for in the book.

How do I solve for the speed while in orbit? The book gives the answer 1.02x10^3 m/s.

Any help is appreciated.