When the displacement in shm is equal to 1/4 of the amplitude xm, what fraction of the total energy is (a) kinetic energy and (b) potential energy? (c) at what displacement, in terms of the amplitude, is the energy of the system half kinetic energy and half potential energy?

An air standard cycle with variable specific heats is executed in a closed system and is composed of the following four processes. 1-2 isentropic compression 100 kpa and 22°c to 600 kpa 2-3 v=constant heat addition to 1500 k 3-4 isentropic expansion to 100 kpa 4-1 p=constant heat rejection to initial state (a) show the cycle on p-v and t-s s (b) calculate the net work output per unit mass (409 kj/kg) (c) determine the thermal efficiency (47.9%)