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Name:
BRIAN NIXON
Attempt:
1 / 3
Out of:
19
Started:
March 8, 2009 12:18am
Finished:
March 9, 2009 5:57am
Time spent:
28 hr, 39 min., 24 sec.
Question 1
(1 point)
A stressstrain graph for a plain carbon steel is shown below.
A cylindrical specimen of this alloy 565 mm long is pulled in tension. What is the
radius
of the specimen if an
elongation of 1.13 mm occurs when a load of 28.2 kN is applied?
Student response:
Percent
Value
Correct
Response
Student
Response
Answer Choices
0.0%
a.
3.08 mm
100.0%
b.
4.74 mm
0.0%
c.
3.55 mm
0.0%
d.
5.18 mm
General feedback: Find the strain using the equation in
6.2 Concepts of Stress and Strain
, then use the graph
to find the stress that produces that strain. Rearranging the equation for stress in section 6.2
to solve for crosssectional area will allow you to find the radius.
Score:
1 / 1
Question 2
(2 points)
A 10 mmdiameter Brinell hardness indenter produced an indentation 1.4 mm in diameter in a steel alloy when a
load of 474 kg was used.
Calculate the
HB
(in HB) of this material.
Use decimal notation, digits after decimal: 0
Student response:
3 HB
Correct answer:
306 HB
General feedback:
The Brinell hardness may be calculated using the following equation:
Page 1 of 5
Learning System Quiz Homepage
3/9/2009
http://webct.mcmaster.ca/SCRIPT/MATLS_1M03_T2_09/scripts/student/serve_quiz_marke.
..
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View Full Document See the
HardnessTesting Techniques Table
in the text for more information.
Score:
0.2 / 2
Question 3
(2 points)
A cylindrical metal specimen is pulled in tension until fracture occurs. The specimen has an original diameter of
8.0 mm and gauge length of 103 mm.
At the point of fracture the diameter is 1.7 mm, and the gauge length is 111 mm. Calculate the ductility in terms
of
percent reduction in area
(in
%
).
Use decimal notation, digits after decimal: 0
Student response:
95 %
Correct answer:
95 %
General feedback: Percent reduction in area is defined by the equation
For more information, see the section on
Tensile Properties: Ductility
in the text.
Score:
2 / 2
Question 4
(1 point)
An alloy to be used for a spring application must have a modulus resilience of at least 8.25 x 10
5
J/m
3
(8.25 x
10
5
Pa).
What must be its minimum yield strength (in MPa)? Assume that the modulus of elasticity for this alloy is 192
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This note was uploaded on 02/08/2010 for the course MATLS 1M03 taught by Professor Okon during the Winter '09 term at McMaster University.
 Winter '09
 OKON

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