How does the rotation of earth affect the value of acceleration due to gravity?
Short answer: the rotation of earth does not affect *gravity* in an appreciable way, but it does affect the downward force you feel while standing on the surface of the earth. This is because the centrifugal fictitious force pulls you outward, and makes it seem as though gravity is weaker (by a couple of percent, if I recall correctly). Check wikipedia about fictitious forces, they can explain them better than I.
