Solutions Manual
Fox and McDonald's Introduction to Fluid Mechanics
10th Edition
By
Robert W. Fox,
Alan T. McDonald,
John W. Mitchell
( All Chapters Included - 100% Verified Solutions )
1
,Problem 1.1 [Difficulty 2]
1.1 Describe the conditions for which the following substances can be considered liquids.
Tar Honey Wax Propane
Carbon dioxide Sea water Sand Toothpaste
Given: Substances
Find: Conditions for which the substances can be considered liquids
Solution:
Tar and Wax behave as solids at room temperature or below at ordinary pressures. At high
pressures or higher temperatures they become viscous fluids.
Honey behaves can behave as a liquid or a solid when it crystalizes
Propane behaves as a liquid at high pressure and a gas at low pressure.
Carbon dioxide behaves as a solid or a gas at room pressure and a liquid at high pressure)
Sea water behaves as a liquid above its freezing point (about 30 F)
Toothpaste behaves as a solid in the tube and becomes a liquid at hig pressure when the tube is
squeezed
Sand acts solid when at rest a liquid when it moves.
2
, Problem 1.2 [Difficulty: 2]
Given: Five basic conservation laws stated in Section 1-4.
Write: A word statement of each, as they apply to a system.
Solution: Assume that laws are to be written for a system.
a. Conservation of mass — The mass of a system is constant by definition.
b. Newton's second law of motion — The net force acting on a system is directly proportional to the product of the
system mass times its acceleration.
c. First law of thermodynamics — The change in stored energy of a system equals the net energy added to the
system as heat and work.
d. Second law of thermodynamics — The entropy of any isolated system cannot decrease during any process
between equilibrium states.
e. Principle of angular momentum — The net torque acting on a system is equal to the rate of change of angular
momentum of the system.
3
, Problem 1.3 [Difficulty: 3]
Open-Ended Problem Statement: The barrel of a bicycle tire pump becomes quite warm during use.
Explain the mechanisms responsible for the temperature increase.
Discussion: Two phenomena are responsible for the temperature increase: (1) friction between the pump piston
and barrel and (2) temperature rise of the air as it is compressed in the pump barrel.
Friction between the pump piston and barrel converts mechanical energy (force on the piston moving through a
distance) into thermal energy as a result of friction. Lubricating the piston helps to provide a good seal with the
pump barrel and reduces friction (and therefore force) between the piston and barrel.
Temperature of the trapped air rises as it is compressed. The compression is not adiabatic because it occurs during a
finite time interval. Heat is transferred from the warm compressed air in the pump barrel to the cooler surroundings.
This raises the temperature of the barrel, making its outside surface warm (or even hot!) to the touch.
4
Fox and McDonald's Introduction to Fluid Mechanics
10th Edition
By
Robert W. Fox,
Alan T. McDonald,
John W. Mitchell
( All Chapters Included - 100% Verified Solutions )
1
,Problem 1.1 [Difficulty 2]
1.1 Describe the conditions for which the following substances can be considered liquids.
Tar Honey Wax Propane
Carbon dioxide Sea water Sand Toothpaste
Given: Substances
Find: Conditions for which the substances can be considered liquids
Solution:
Tar and Wax behave as solids at room temperature or below at ordinary pressures. At high
pressures or higher temperatures they become viscous fluids.
Honey behaves can behave as a liquid or a solid when it crystalizes
Propane behaves as a liquid at high pressure and a gas at low pressure.
Carbon dioxide behaves as a solid or a gas at room pressure and a liquid at high pressure)
Sea water behaves as a liquid above its freezing point (about 30 F)
Toothpaste behaves as a solid in the tube and becomes a liquid at hig pressure when the tube is
squeezed
Sand acts solid when at rest a liquid when it moves.
2
, Problem 1.2 [Difficulty: 2]
Given: Five basic conservation laws stated in Section 1-4.
Write: A word statement of each, as they apply to a system.
Solution: Assume that laws are to be written for a system.
a. Conservation of mass — The mass of a system is constant by definition.
b. Newton's second law of motion — The net force acting on a system is directly proportional to the product of the
system mass times its acceleration.
c. First law of thermodynamics — The change in stored energy of a system equals the net energy added to the
system as heat and work.
d. Second law of thermodynamics — The entropy of any isolated system cannot decrease during any process
between equilibrium states.
e. Principle of angular momentum — The net torque acting on a system is equal to the rate of change of angular
momentum of the system.
3
, Problem 1.3 [Difficulty: 3]
Open-Ended Problem Statement: The barrel of a bicycle tire pump becomes quite warm during use.
Explain the mechanisms responsible for the temperature increase.
Discussion: Two phenomena are responsible for the temperature increase: (1) friction between the pump piston
and barrel and (2) temperature rise of the air as it is compressed in the pump barrel.
Friction between the pump piston and barrel converts mechanical energy (force on the piston moving through a
distance) into thermal energy as a result of friction. Lubricating the piston helps to provide a good seal with the
pump barrel and reduces friction (and therefore force) between the piston and barrel.
Temperature of the trapped air rises as it is compressed. The compression is not adiabatic because it occurs during a
finite time interval. Heat is transferred from the warm compressed air in the pump barrel to the cooler surroundings.
This raises the temperature of the barrel, making its outside surface warm (or even hot!) to the touch.
4
