Understanding Motor Controls
4th Edition
ISBN: 9781337798686
Author: Stephen L. Herman
Publisher: Delmar Cengage Learning
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Chapter 1, Problem 7RQ
To determine
The most common method of controlling the speed of an alternating current motor.
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250 mm
400 mm
A
B
C
E
F
250 mm
PROBLEM 1.52
Each of the two vertical links CF connecting the two horizontal
members AD and EG has a 10 × 40-mm uniform rectangular cross
section and is made of a steel with an ultimate strength in tension of
400 MPa, while each of the pins at C and F has a 20-mm diameter and
are made of a steel with an ultimate strength in shear of 150 MPa.
Determine the overall factor of safety for the links CF and the pins
connecting them to the horizontal members.
24 kN
50 mm
12 mm
B
O
C
OA
300 mm
450 mm
E
PROBLEM 1.51
Each of the steel links AB and CD is connected to a support and to
member BCE by 25-mm-diameter steel pins acting in single shear.
Knowing that the ultimate shearing stress is 210 MPa for the steel
used in the pins and that the ultimate normal stress is 490 MPa for
the steel used in the links, determine the allowable load P if an
overall factor of safety of 3.0 is desired. (Note that the links are not
reinforced around the pin holes.)
3. A 15% magnesium chloride solution is flowing through a 5-nom sch 40 commercial steel pipe
at a rate of 325,000 lbm/h. The average temperature of the magnesium chloride solution as it flows
through the pipe is 10°F. Determine the convective heat transfer coefficient inside the pipe.
Chapter 1 Solutions
Understanding Motor Controls
Ch. 1 - When installing a motor control system, list four...Ch. 1 - Prob. 2RQCh. 1 - Is the National Electrical Code a law?Ch. 1 - Explain the difference between manual control,...Ch. 1 - Prob. 5RQCh. 1 - Explain the difference between jogging and...Ch. 1 - Prob. 7RQCh. 1 - What agency requires employers to provide a...Ch. 1 - What is meant by the term ramping?
Ch. 1 - What is the most important function of any control...
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