A five-story office building has stairs that are each 7 inches tall. Carol, who works on the top floor of the building, says that the change in height for each stair should be represented by −7. Dave, who works on the first floor, thinks that the change in height should be represented by +7. Who do you think is correct? Support your answer with your reason

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.