Air initially at 0.1 mpa, 27 °c, is compressed reversibly to a final state. (a) find the entropy change of the air when the final state is 0.5 mpa, 227°c (b) find the entropy change when the final state is 0.5 mpa, 180°c. (c) find the temperature at 0.5 mpa that makes the entropy change zero.

An engine, weighing 3000 n, is supported on a pedestal mount. it has been observed that the engine induces vibration into the surrounding area through its pedestal at the maximum operating speed. determine the stiffness of the dynamic vibration absorber spring in (n/m) that will reduce the vibration when mounted on the pedestal. the magnitude of the exciting force is 250 n, and the amplitude of motion of the auxiliary mass is to be limited to 2 mm note: in this question type-in right numbers, no decimals, no fractions, no unit. approximate to right number if needed