If one afternoon mike gauthier decides to dig a hole through the earth to china for a game of ping pong, how many centuries would elapse before he got there if he dug at a rate of 0.400 miles depth per day and the diameter of the earth is 1.2700 e 7 m?

Wo small variable-thrust jets are actuated to keep the spacecraft angular velocity about the z-axis constant at ? 0 = 1.16 rad/s as the two telescoping booms are extended from r1 = 1.18 m to r2 = 4.69 m at a constant rate over a period of 124 seconds. the small 19-kg experiment modules at the ends of the booms may be treated as particles, and the mass of the rigid booms is negligible. determine the necessary thrust t for each jet as a function of time where t = 0 is the time when the telescoping action is begun. after you have the general expression for t, answer the questions. show work.