1.36 Liquid kerosene flows through a Venturi meter, as shown in Fig. P1.36. The pressure of
the kerosene in the pipe supports columns of kerosene that differ in height by 12 cm. Determine
the difference in pressure between points a and b, in kPa. Does the
Complete the following exercise using heat transfer relations:
(a) Referring to Fig. 2.12, determine the rate of conduction heat transfer, in W, for = 0.07
W/mK, A = 0.125 m2, T1 = 298 K, T2 = 273 K.
(b) Referring to Fig. 2.14, determine the
Note: Minus signs
signify energy transfer
by work to the gas.
Carbon monoxide gas (CO) contained within a piston-cylinder assembly undergoes three
processes in series:
Process 1-2: Constant pressure expansion at 5 bar from V1 = 0
Since the gage pressure of the air in tank A is a vacuum, Eq. 1.15 applies.
p(vacuum) = patm(absolute) p(absolute)
The pressure of the gas in tank B is the local atmospheric pressure to tank A. Solving for p
(absolute) and substituting values yield
1.31 A gas contained within a piston-cylinder assembly undergoes four processes in series:
Process 1-2: Constant-pressure expansion at 1 bar from V1 = 0.5 m3 to V2 = 2 m3
Process 2-3: Constant volume to 2 bar
Process 3-4: Constant-pressure compression to
1.52 Water in a swimming pool has a temperature of 24oC. Express this temperature in K, oF,
KNOWN: Water is at a specified temperature in oC.
FIND: Equivalent temperature in K, oF, and oR.
SCHEMATIC AND GIVEN DATA:
T = 24oC
To determine the corresponding weights in lbf, apply the conversion factor, 1 lbf = 4.4482 N.
WSat(Earth) (4400 N)
= 989.2 lbf
WSat(orbit) (100.5 N)
= 22.6 lbf
1.21 A 2-lb sample of an unknown liquid occupies a volume of 62
1.17 A communications satellite weighs 4400 N on Earth where g = 9.81 m/s2. What is the
weight of the satellite, in N, as it orbits Earth where the acceleration of gravity is 0.224 m/s2?
Express each weight in lbf.
KNOWN: Weight of communications satellit
Problem 2.31 (Contd)
Air contained within a piston-cylinder assembly is slowly compressed. As shown in Fig P2.32,
during this first process the pressure first varies linearly with volume and then remains constant.
1.8 The Phoenix with a mass of 350 kg was a spacecraft used for exploration of Mars.
Determine the weight of the Phoenix, in N, (a) on the surface of Mars where the acceleration of
gravity is 3.73 m/s2 and (b) on Earth where the acceleration of gravity is
(b) Draw a second free body diagram indicating all forces acting on the piston including the
newly added weight expressed as the product of its mass and gravitational acceleration. Taking
upward as the positive y-direction, the sum of the forces acting on
1.41 As shown in Figure P1.41, air is contained in a vertical piston-cylinder assembly such
that the piston is in static equilibrium. The atmosphere exerts a pressure of 14.7 lbf/in.2 on top of
the 6-in.-diameter piston. The absolute pressure of the air i
1.23 The specific volume of 5 kg of water vapor at 1.5 MPa, 440oC is 0.2160 m3/kg. Determine
(a) the volume, in m3, occupied by the water vapor, (b) the amount of water vapor present, in
gram moles, and (c) the number of molecules.
KNOWN: Mass, pressure,
Two objects having different masses are propelled vertically from the surface of Earth, each with
the same initial velocities. Assuming the objects are acted upon only by the force of gravity,
show that they reach zero velocity at the same he
Carbon dioxide (CO2) gas within a piston-cylinder assembly undergoes a process from a state
where p1 = 5 lbf/in.2, V1 = 2.5 ft3 to a state where p2 = 20 lbf/in.2, V2 = 0.5 ft3. The relationship
between pressure and volume during
An electric motor draws a current of 10 amp with a voltage of 110 V, as shown in Fig. P2.62.
The output shaft develops a torque of 9.7 Nm and a rotational speed of 1000 RPM. For
operation at steady state, determine f
Energy consumption per capita
Scrutineering Gate 2
TEAM NUMBER: 7
DATE & WEEK NUMBER:
Yes or No
WIND LOADING & STRUCTURE
Summary of blade design
data with known sizes,
expected wind speeds and
Wind SpeedsGhana 4ms
Population density Ghana 267per square mile
Bangladesh 2877 per square mile
Philippines 888 per square mile
Fiji 119 per square mile
Global estimate of 19.3 million displacement per year aroun
Problem 2.35 (Continued)
Inserting values and converting units
= -11.92 Btu (in)
Process 2-3: Constant volume (piston does not move). Thus W23 = 0
Process 3-1: Constant pressure processes (p3 = p1):
Noting that V3 = V2
= 5.92 Btu (out)
1. The net work for
PROBLEM 2.49 (CONTINUED)
A composite plane wall consists of a 3-in.-thick layer of insulation (i = 0.029 Btu/hftoR) and a
0.75-in.-thick layer of siding (s = 0.058 Btu/hftoR). The inner temperature of the insulation is
A construction crane weighing 12,000 lbf fell from a height of 400 ft to the street below during a
severe storm. For g = 32.05 ft/s2, determine mass, in lb, and the change in gravitational potential
energy of the crane, in ftlbf.
KNOWN: A cran
1.27 Three kg of gas in a piston-cylinder assembly undergo a process during which the
relationship between pressure and specific volume is pv0.5 = constant. The process begins with
p1 = 250 kPa and V1 = 1.5 m3 and ends with p2 = 100 kPa. Determine the fin
Each line of the following table gives data for a process of a closed system. Each entry has the
same energy units. Determine the missing entries.
Perform the following unit conversions:
(a) 1 L
0.0353 ft 3 12 in.
(b) 650 J
103 J 1.0551 kJ
(c) 0.135 kW
3413 Btu/h 1 h 778.17 ft lbf
g 1 kg
s 10 3
1.58 Left for independent study using the Internet.
Determine the gravitational potential energy, in kJ, of 2 m3 of liquid water at an elevation of
30 m above the surface of Earth. The acceleration of gravity is constant at 9.7 m/s2 and the