Exercícios resolvidos

Exercícios resolvidos

(Parte 1 de 6)





Concept-Study Guide Problems1-2
Properties and Units23-26
Force and Energy27-37
Specific Volume38-43
Manometers and Barometers58-76

Correspondence table Review Problems 81-86

Sonntag, Borgnakke and van Wylen

CHAPTER 2 6th editionSonntag/Borgnakke/Wylen

Correspondence table

The correspondence between the problem set in this sixth edition versus the problem set in the 5'th edition text. Problems that are new are marked new and those that are only slightly altered are marked as modified (mod).

Study guide problems 2.1-2.2 and 2.23-2.26 are all new problems.

New 5th Ed. New 5th Ed. New 5th Ed. 27 1 47 new 67 24 28 new 48 16 68 new 29 2 49 17 69 new 30 new 50 new 70 23 31 3 51 new 71 new 32 new 52 19 72 30 3 5 53 new 73 32 34 6 54 34 74 3 35 7 5 29 75 new 36 9 56 new 76 37 37 10 57 28 mod 7 27 38 12 58 new 78 new 39 new 59 20 79 38 40 new 60 26 80 new 41 new 61 new 81 31 42 1 62 21 82 new 43 13 63 new 83 2 4 new 64 new 84 35 45 18 65 15 85 36 46 14 6 new 86 new

English Unit Problems

96 42E 42

New 5th Ed. SI New 5th Ed. SI 87 new - 97 43E 43 8 new 1 98 new 50 89 new 12 9 new 53 90 new 19 100 45E 70 91 new 20 101 46E 45 92 new 24 102 new 82 93 39E 3 103 48E 5 94 40E - 104 new 80 95 new 47 105 47E 7 Design and Open ended problems 106-116 are from 5th edition problems 2.50- 2.60

Sonntag, Borgnakke and van Wylen

Concept-Study Guide Problems

Make a control volume around the turbine in the steam power plant in Fig. 1.1 and list the flows of mass and energy that are there.


We see hot high pressure steam flowing in at state 1 from the steam drum through a flow control (not shown). The steam leaves at a lower pressure to the condenser (heat exchanger) at state 2. A rotating shaft gives a rate of energy (power) to the electric generator set.

Sonntag, Borgnakke and van Wylen

Make a control volume around the whole power plant in Figure 1.2 and with the help of Fig. 1.1 list what flows of mass and energy are in or out and any storage of energy. Make sure you know what is inside and what is outside your chosen C.V.


SmokestackBoiler building

Coal conveyor system

Dock Turbine house

Storage gypsum

Coal storage flue gas

Undergroundpower cable Welectrical

Hot waterDistrict heating m

Coal m

Flue gas

Storage for later

Gypsum, fly ash, slagtransport out: Cold returnm

Combustion air

Sonntag, Borgnakke and van Wylen

Make a control volume that includes the steam flow around in the main turbine loop in the nuclear propulsion system in Fig.1.3. Identify mass flows (hot or cold) and energy transfers that enter or leave the C.V.


Electric power gen.

Condensate to steam gen. cold

Hot steam from generator

The electrical power also leaves the C.V. to be used for lights, instruments and to charge the batteries.

Sonntag, Borgnakke and van Wylen

Take a control volume around your kitchen refrigerator and indicate where the components shown in Figure 1.6 are located and show all flows of energy transfer.


The valve and the cold line, the evaporator, is inside close to the inside wall and usually a small blower distributes cold air from the freezer box to the refrigerator room.

Q. Q leak

The black grille in the back or at the bottom is the condenser that gives heat to the room air.

The compressor sits at the bottom.

Sonntag, Borgnakke and van Wylen

An electric dip heater is put into a cup of water and heats it from 20oC to 80oC. Show the energy flow(s) and storage and explain what changes.


Electric power is converted in the heater element (an electric resistor) so it becomes hot and gives energy by heat transfer to the water. The water heats up and thus stores energy and as it is warmer than the cup material it heats the cup which also stores some energy. The cup being warmer than the air gives a smaller amount of energy (a rate) to the air as a heat loss.

(Parte 1 de 6)