Mechanical Engineering Answers

If a gas of volume 0.06 m3

and at pressure 100kPa is compressed quasistatically according to

pV2 =C until the volume become 0.02m3

, determine the final pressure and the work transfer.

An ideal Otto cycle using air has the following conditions. At point 1; p1 = 14.5 psia and 80° F. The heat added to the air is 370 BTU/lbm per cycle. If the maximum temperature is 3400 °R and K = 1.4, Compute the pressure, temperature and volume at each corner of the cycle; the compression ratio, mean effective BTU pressure and the cycle thermal efficiency if cv= 0.172 lb m-°R

A dual cycle using air operates at 14.7 psia, 70°F_and r = 7. The cylinder diameter of the engine is 10 inches and the stroke is 12 inches. The pressure at the end of isometric heating process is 800 psia. If heat is added at constant pressure during 3% of the stroke, compute the net work and cycle thermal efficiency. The atmosphere is at 14.7 psia and 70° F.

At the beginning of compression in an ideal air standard Diesel cycle, the compression ratio is 16 with p1 = 100 kPa and T1= 300K. The maximum temperature of the cycle is 2000K. If cp = 1.005 kJ/ kgm-K and cv= 0.718- kJ/kgm-°K for the air, compute (a) the pressure, temperature and volume at four corners of the cycle. (b) the heat transfer (c) the work done per kgm for each process, and (d) the cycle thermal efficiency.

A mass of 4 kg is suspended from a spring and oscillates up and down at 2 Hz. Determine the stiffness of the spring. (631.6 N/m). The amplitude of the oscillation is 5 mm. Determine the displacement. velocity and acceleration 0.02 s after the mass passes through the mean or rest position in an upwards direction. (1.243 mm. 60.86 nm's and -196.4 m/s) I

Steam undergoes an isentalpic (h=C) process from 1.5 MPa, 350°C to 10 MPa. Find the final temperature using the Mollier chart.

5. Compute for the enthalpy, internal energy, and entropy of steam at 72oC and 93%

quality. Please explain?

4. What is the quality of steam at 248oC and having an enthalpy of 2100 kJ/kg?

3. Compute the moisture content of steam at 20 kPa, entropy of 6.3 kJ/kg-K.

2. Find the enthalpy at 5 MPa, 8.2% moisture content.