Askateboarder wants to cross a large playground and notices that there are large shapes painted on its asphalt surface. one shape is a large circle that covers the entire playground. inscribed in that circle is a square, with one point at the skateboarder’s feet and the other at his destination. the surface is rough and, therefore, friction is present. what path does he follow in order to minimize the work done by nonconservative forces?

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.