The Position of the Moon Relative to the center of the Earth, the position of the Moon can...

The Position of the Moon Relative to the center of the Earth, the position of the Moon can be approximated by

where t is measured in seconds. (a) Find the magnitude and direction of the Moon’s average velocity between t = 0 and t = 7.38 days. (This time is one-quarter of the 29.5 days it takes the Moon to complete one orbit.) (b) Is the instantaneous speed of the Moon greater than, less than, or the same as the average speed found in part (a)? Explain.