To warm up some milk for a baby, a mother pours milk into a thin-walled cylindrical container whose diameter is 6 cm. The height of the milk in the container is 7 cm. She then places the container into a large pan filled with hot water at 70°C. The milk is stirred constantly so that its temperature is uniform at all times. If the heat transfer coefficient between the water and the container is 120 W/m 2 K, determine how long it will take for the milk to warm up from 3°C to 38°C. Assume the entire surface area of the cylindrical container (including the top and bottom) is in thermal contact with the hot water. Take the properties of the milk to be the same as those of water. Can the milk in this case be treated as a lumped system? Why?
To warm up some milk for a baby, a mother pours milk into a thin-walled cylindrical container whose diameter is 6 cm. The height of the milk in the container is 7 cm. She then places the container into a large pan filled with hot water at 70°C. The milk is stirred constantly so that its temperature is uniform at all times. If the heat transfer coefficient between the water and the container is 120 W/m 2 K, determine how long it will take for the milk to warm up from 3°C to 38°C. Assume the entire surface area of the cylindrical container (including the top and bottom) is in thermal contact with the hot water. Take the properties of the milk to be the same as those of water. Can the milk in this case be treated as a lumped system? Why?
Solution Summary: The author explains that milk can be treated as a lumped system, as the temperature of the milk is assumed to remain constant every time.
To warm up some milk for a baby, a mother pours milk into a thin-walled cylindrical container whose diameter is 6 cm. The height of the milk in the container is 7 cm. She then places the container into a large pan filled with hot water at 70°C. The milk is stirred constantly so that its temperature is uniform at all times. If the heat transfer coefficient between the water and the container is 120 W/m2 K, determine how long it will take for the milk to warm up from 3°C to 38°C. Assume the entire surface area of the cylindrical container (including the top and bottom) is in thermal contact with the hot water. Take the properties of the milk to be the same as those of water. Can the milk in this case be treated as a lumped system? Why?
Multiple Choice
Circle the best answer to each statement.
1. Which type of surface deviation is controlled by a cy-
lindricity tolerance but not by a circularity tolerance?
A.
B.
C.
Ovality
Taper
Lobing
D. None of the above
2. When verifying a cylindricity tolerance, the inspec-
tion method must be able to collect a set of points and
determine the:
A. Distance between two coaxial cylinders that con-
tain the set of points
B.
Cylinder that circumscribes the set of points
C. Cylinder that inscribes the set of points
D.
Distance between two coaxial circles that contain
the set of points
3. Where Rule #1 applies to a cylindrical regular feature
of size, the tolerance value of a cylindricity tolerance
applied to the feature of size must be
tolerance.
A. Less than
B. Equal to
C. Greater than
D. None of the above
the size
4. Which of the following modifiers may be applied with
a cylindricity tolerance?
A. M
B.
C. ℗
D. Ø
5. Which geometric tolerance can provide an indirect
cylindricity…
The beam AB is attached to the wall in the xz plane by a
fixed support at A. A force of
F = (−129î + 69.0ĵ + 3591) N is applied to the end of
the beam at B. The weight of the beam can be modeled with
a uniform distributed load of intensity w = 85.0 N/m acting in
the negative z direction along its entire length. Find the
support reactions at A.
Z
с
A
b
a
B
F
y
Cc 10
BY NC SA
2016 Eric Davishahl
X
Values for dimensions on the figure are given in the following.
table. Note the figure may not be to scale.
Variable
Value
a
5.60 m
b
5.00 m
C
3.70 m
A
II
=
MA = (
m
2.>
~.>
+
+
k) N
k) N-
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, mechanical-engineering and related others by exploring similar questions and additional content below.