Thermo Fluids
Solutions (Week-01)
Chapter-01
1-12 A plastic tank is filled with water. The weight of the combined system is to be determined.
Assumptions The density of water is constant throughout.
Properties The density of water is given to be = 1000 kg/m3.
Analysis The mass of the water in the tank and the total mass are
mw =V =(1000 kg/m3)(0.2 m3) = 200 kg mtotal = mw + mtank = 200 + 3 = 203 kg
Thus,
1-14 The variation of gravitational acceleration above the sea level is given as a function of altitude. The height at which the weight of a body will decrease by 1% is to be determined.
Analysis The weight of a body at the elevation z can be expressed as In our case, Substituting,
1-30 The gravitational acceleration changes with altitude. Accounting for this variation, the weights of a body at different locations are to be determined.
Analysis The weight of an 80-kg man at various locations is obtained by substituting the altitude z (values in m) into the relation
Sea level: (z = 0 m): W = 80(9.807-3.32x10-60) = 809.807 = 784.6 N Denver: (z = 1610 m): W = 80(9.807-3.32x10-61610) = 809.802 = 784.2 N Mt. Ev.: (z = 8848 m): W = 80(9.807-3.32x10-68848) = 809.778 = 782.2 N
Chapter -02
2-4C In electric heaters, electrical energy is converted to sensible internal energy.
2-11C A process during which a system remains almost in equilibrium at all times is called a quasi-equilibrium process. Many engineering processes can be approximated as being quasi-equilibrium. The work output of a device is maximum and the work input to a device is minimum when quasi-equilibrium processes are used instead of nonquasi-equilibrium processes.
2-21C Carbon dioxide (CO2), water vapor, and trace amounts of some other gases such as methane and nitrogen oxides act like a blanket and keep the earth warm at night by blocking the heat radiated from the earth. This is known as the greenhouse effect. The greenhouse effect makes
Chapter-01
1-12 A plastic tank is filled with water. The weight of the combined system is to be determined.
Assumptions The density of water is constant throughout.
Properties The density of water is given to be = 1000 kg/m3.
Analysis The mass of the water in the tank and the total mass are
mw =V =(1000 kg/m3)(0.2 m3) = 200 kg mtotal = mw + mtank = 200 + 3 = 203 kg
Thus,
1-14 The variation of gravitational acceleration above the sea level is given as a function of altitude. The height at which the weight of a body will decrease by 1% is to be determined.
Analysis The weight of a body at the elevation z can be expressed as In our case, Substituting,
1-30 The gravitational acceleration changes with altitude. Accounting for this variation, the weights of a body at different locations are to be determined.
Analysis The weight of an 80-kg man at various locations is obtained by substituting the altitude z (values in m) into the relation
Sea level: (z = 0 m): W = 80(9.807-3.32x10-60) = 809.807 = 784.6 N Denver: (z = 1610 m): W = 80(9.807-3.32x10-61610) = 809.802 = 784.2 N Mt. Ev.: (z = 8848 m): W = 80(9.807-3.32x10-68848) = 809.778 = 782.2 N
Chapter -02
2-4C In electric heaters, electrical energy is converted to sensible internal energy.
2-11C A process during which a system remains almost in equilibrium at all times is called a quasi-equilibrium process. Many engineering processes can be approximated as being quasi-equilibrium. The work output of a device is maximum and the work input to a device is minimum when quasi-equilibrium processes are used instead of nonquasi-equilibrium processes.
2-21C Carbon dioxide (CO2), water vapor, and trace amounts of some other gases such as methane and nitrogen oxides act like a blanket and keep the earth warm at night by blocking the heat radiated from the earth. This is known as the greenhouse effect. The greenhouse effect makes