Statement
difficulty
Determine the centripetal acceleration of the Moon knowing that a complete orbit around the Earth takes 27.32 days (sidereal period) and the average distance is 384000 km.
Solution
Data
- Period T = 27.32 days = 27.32 · 24 hours/day · 60 minutes/hour · 60 seconds/minute = 2360448 s
- Radius R = 384000 km = 3.84·108 m
Preliminary considerations
Normal or centripetal acceleration is responsible for the change of direction of the velocity vector. It is the only type of acceleration in uniform circular motion.
Resolution
Applying the expression of normal or centripetal acceleration, we get the value we are looking for: