Number 10.18, 10.19 . Please help me

10.18. In a tunnel at a diance h below Earth's surface, the &nsity of Earth's material is A. will the change in the of a clock pendulum, that is, AT/T, at this depth? Will the run fast or slow? Calculate your answer in terms of h, M, RE. and Ph. If we measure AT/ T exFimen- tally, cnn we determine Earths mass, knowing the other variables? 10.19. Consider a thin cylindrical rod of length L, radius a, and mass M. Calculate gravitational pcential and the yavitational field intensity at a distance r from the center of the and in a rzndicularto the rd Graph the results. 10.20. Consida a thin o lenpth L and mass M. Calculate the gravitational and era