A cart with a mass of 8.0 kilograms is attached to a spring. When released from the spring, the cart travels up a hill with a height of 11
meters. The cart comes to rest at the top of the hill. The spring is 100%
efficient. How much elastic potential energy was required to bring the
cart to rest at the top of the hill? Include your units.

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.