Question bank
A piston/cylinder with a cross-sectional area of 0.01 m2 has a piston mass of 100 kg
resting on the stops, as shown in Figure. With an outside atmospheric pressure of
100 kPa, what should the water pressure be to lift the piston?
Water in a piston/cylinder is at 101 kPa, 25 C, and mass 0.5 kg. The piston rests on
some stops, and the pressure should be 1000 kPa to float the piston. We now heat
the water, so the piston just reaches the end of the cylinder. Find the total heat
transfer.
A piston/cylinder arrangement, shown in Figure, contains air at 250 kPa and 300C.
The 50-kg piston has a diameter of 0.1 m and initially pushes against the stops. The
atmosphere is at 100 kPa and 20C. The cylinder now cools as heat is transferred to
the ambient surroundings.
a. At what temperature does the piston begin to move down?
b. How far has the piston dropped when the temperature reaches ambient?
c. Show the process in a P–v and a T–v diagram.
cylinder has a thick piston initially held by a pin, as shown in Figure. The cylinder
contains carbon dioxide at 200 kPa and ambient temperature of 290 K. The metal
piston has a density of 8000 kg/m3 and the atmospheric pressure is 101 kPa. The
pin is now removed, allowing the piston to move, and after a while the gas returns
to ambient temperature. Is the piston against the stops?
cylinder/piston arrangement contains water at 105C, 85% quality, with a volume of
1 L. The system is heated, causing the piston to rise and encounter a linear spring,
as shown in Figure At this point the volume is 1.5 L, the piston diameter is 150 mm,
and the spring constant is 100 N/mm. The heating continues, so the piston
compresses the spring. What is the cylinder temperature when the pressure
reaches 200 kPa?
A piston/cylinder arrangement is loaded with a linear spring and the outside
atmosphere. It contains water at 5 MPa, 400C, with the volume being 0.1m3, as
shown in Figure. If the piston is at the bottom, the spring exerts a force such that
Plift =200 kPa. The system now cools until the pressure reaches 1200 kPa. Find the
mass of water and the final state (T2, v2) and plot the P–v diagram for the process.
Two kilograms of water is contained in a piston/ cylinder with a massless piston loaded with a linear spring
and the outside atmosphere. Initially the spring force is zero and P1 = P0 =100 kPa with a volume of 0.2m3.
If the piston just hits the upper stops, the volume is 0.8 m3 and T = 600 C. Heat is now added until the
pressure reaches 1.2 MPa. Show the P–V diagram and find the work and heat transfer for the process.
Consider the piston/cylinder arrangement shown in Figure. A frictionless piston is free to move between
two sets of stops. When the piston rests on the lower stops, the enclosed volume is 400 L. When the
piston reaches the upper stops, the volume is 600 L. The cylinder initially contains water at 100 kPa, with
20% quality. It is heated until the water eventually exists as saturated vapor. The mass of the piston
requires 300 kPa pressure to move it against the outside ambient pressure. Determine the final pressure
in the cylinder,
ÇENGEL reference
Chapter 3
28,,34,51,63,57,118,120
Chapter 4
7,10,4E,5,14,18,24,28,31,34,35,38,64,65,66,68,70 ,130,138,71,131,139