ABSTRACT
Problem 2. In an isothermal process, a mass of gas has its volume reduced from 3200 mm3 to 2000 mm3. If the initial pressure of the gas is 110 kPa, determine the final pressure.
Since the process is isothermal, it takes place at constant temperature and hence Boyle’s law applies, i.e. p1V1 = p2V2, where p2 = 110 kPa, V1 = 3200 mm
3 and V2 = 2000 mm
3. Hence, (110)(3200) = p2(2000)
from which, final pressure, p2 = ×110 3200 2000
= 176 kPa
Problem 3. Some gas occupies a volume of 1.5 m3 in a cylinder at a pressure of 250 kPa. A piston, sliding in the cylinder, compresses the gas isothermally until the volume is 0.5 m3. If the area of the piston is 300 cm2, calculate the force on the piston when the gas is compressed.
