Air is compressed from 1 bar and 27c (state 1) to 2.1 bar (state 2) in an axial flow compressor. work required for the compression process is 94.6 kj/kg. heat transfer of 14 kj/kg occurs from the compressor to the surroundings at an average surface temperature of 40c. assume that the surrounding pressure is 1 bar and temperature is 20c. consider variable specific heats for air. molecular weight of air = 28.97 kg/kmol. (a) calculate temperature (k) of air at the compressor exit. (b) find the exergy destroyed (kj/kg) during the compression process using entropy generation. (c) perform an exergy accounting of the compressor. answers: (a) 380 k; (b) 20.5 kj/kg

Natural forces that can alter ecosystems include seasons and climate changes. t or f

Follow these directions and answer the questions. 1. set up the ripple tank as in previous investigations. 2. bend the rubber tube to form a "concave mirror" and place in the ripple tank. the water level must be below the top of the hose. 3. generate a few straight pulses with the dowel and observe the reflected waves. do the waves focus (come together) upon reflection? can you locate the place where the waves meet? 4. touch the water surface where the waves converged. what happens to the reflected wave? 5. move your finger twice that distance from the hose (2f = c of c, center of the curvature) and touch the water again. does the image (the reflected wave) appear in the same location (c of c)? you may have to experiment before you find the exact location. sometimes it is hard to visualize with the ripple tank because the waves move so quickly. likewise, it is impossible to "see" light waves because they have such small wavelengths and move at the speed of light. however, both are examples of transverse waves and behave in the same way when a parallel wave fronts hit a curved surface.

A( developed during the process of technology design