The motion of a linear oscillator may be represented by means of a graph in which x is shown as abscissa and dx/dt as ordinate. the history of the oscillator is then a curve. (a) show that for an undamped oscillator this curve is an ellipse. (b) show (at least qualitatively) that if a damping term is intro- duced one gets a curve spiraling into the origin.

Arefrigerator uses r-134a as the working fluid and operates on the ideal vapor-compression refrigeration cycle except for the compression process. the refrigerant enters the evaporator at 120 kpa with a quality of 34 percent and leaves the compressor at 70°c. if the compressor consumes 450 w of power, determine (a) the mass flow rate of the refrigerant, (b) the condenser pressure, and (c) the cop of the refrigerator. (0.00644 kg/s, 800 kpa, 2.03)