-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathReadingGuide_Ch12_Solution.html
More file actions
125 lines (91 loc) · 5.21 KB
/
ReadingGuide_Ch12_Solution.html
File metadata and controls
125 lines (91 loc) · 5.21 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
<?xml version="1.0" encoding="iso-8859-1"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="content-type" content="text/html; charset=iso-8859-1" />
<title>ReadingGuide_Ch12_Solution</title>
<meta name="generator" content="Amaya, see http://www.w3.org/Amaya/" />
<link rel="stylesheet" href="vishidestyle.css" />
</head>
<body>
<h1>Chapter 12 – Static Equilibrium and Elasticity</h1>
<h3>Introduction</h3>
<p>- The Stilt walkers in Figure 12.1 are standing still so all forces acting
on them cancel out, all torques on them balance out, they are in _________
equilibrium? <span id="ans">Static.</span></p>
<h3>12.1 – Conditions for Static Equilibrium</h3>
<p>- What is equilibrium? Static equilibrium? <span id="ans">An object is in
equilibrium if both its linear and angular acceleration are zero relative to an
inertial frame of reference. Static equilibrium occurs when an object is at
rest in the frame of reference. </span></p>
<p>- What is the first equilibrium condition? <span id="ans">The sum of the
forces on an object must sum to zero. Equation 12.2.</span></p>
<p>- What is the first equilibrium condition? <span id="ans">The sum of the
torques acting on an object sum to zero. Equation 12.5.</span></p>
<p>- When applying equilibrium conditions to a rigid body, what should you
choose as the origin (pivot point)? <span id="ans">You are free to choose any
point as the origin of the reference frame.</span></p>
<p>- What is a center of gravity? <span id="ans">The center of mass of an
object, where the weight vector should be attached. </span></p>
<p>- When does gravitational torque occur on an object? This can be seen in
Figure 12.3. <span id="ans">When the center of mass is located off the pivot
point.</span></p>
<p>- In Example 12.1 (Center of Gravity of a Car), which equations are the
equilibrium conditions? <span id="ans">1st - Equation 12.11. 2nd - Equation
12.12.</span></p>
<p>- In Example 12.2 (A Breaking Tension), notice that there are no rigid
bodies to cause torque, so the 2nd equilibrium condition isn't required but the
1st condition must be applied in both the x and y directions. </p>
<h3>12.2 – Example of Static Equilibrium</h3>
<p>- What is the problem solving strategy for solving problems involving static
equilibrium? <span id="ans">1. Identify the object to be analyzed. Identify all
forces acting on the object. 2. Set up a free-body diagram for the object. (a)
Choose the xy-reference frame for the problem. Draw a freebody diagram for the
object, including only the forces that act on it. On the free-body diagram,
indicate the location of the pivot and the lever arms of acting forces. 3. Set
up the equations of equilibrium for the object. 5. Evaluate the expressions for
the unknown quantities that you obtained in your solution.</span></p>
<p>- Example 12.3 (The Torque Balance) is similar to what you will do in lab.
</p>
<p>- For all of the examples in this section, be able to identify the equations
for equlibium and understand how to get them. </p>
<p>- Example 12.4 (Forces in the Forearm) shows the forces acting on the
forearm, this is static equilibrium on the body.</p>
<h3>12.3 – Stress, Strain, and Elastic Modulus</h3>
<p>- What is stress? <span id="ans">Quantity that describes the magnitude of
forces that cause deformation. Generally stress per area.</span></p>
<p>- What is tensile, bulk, and shear stress?<span id="ans">Tensile -
elongation, bulk - squeezing from all sides, shear - tangential forces.
</span></p>
<p>- What is a pascal? What other base Si units is it equivalent to? <span
id="ans">SI unit of force. 1 Pa = 1N/m^2.</span></p>
<p>- What is strain? <span id="ans">Fractional change in either length of
volume or geometry. </span></p>
<p>- What equation relates stress and strain? <span id="ans">Equation
12.33.</span></p>
<p>- What stress does each modulus correspond to? <span id="ans">Young's -
tensile stress, bulk - bulk stress, shear - shear stress. </span></p>
<p>- What is the equation for Young's modulus? <span id="ans">Equation
12.36.</span></p>
<p>- What is normal pressure? <span id="ans">The typical atmospheric pressure
of one atmosphere. </span></p>
<p>- What is the equation for bulk modulus? <span id="ans">Equation 12.39.
</span></p>
<p>- What is compressibility? The inverse of bulk modulus. <span
id="ans">Describes the change in volume of a fluid per unit increase of
pressure. </span></p>
<p>- What is the equation for shear modulus? <span id="ans">Equation
12.43.</span></p>
<p></p>
<h3>12.4 – Elasticity and Plasticity</h3>
<p>- What does it mean for an object to be elastic? What is the elastic limit?
<span id="ans">The object goes back to its original shape when the load isn't
present. The stress limit where the object is permanently deformed.</span></p>
<p>- What is plastic behavior? <span id="ans">The behavior of an object when it
deforms irreversibly and does not return to its original shape when the load is
removed. </span></p>
<p>- What is a stress-strain diagram? <span id="ans">Graph of the relationship
between stress and strain. An example one is Figure 12.25.</span></p>
</body>
</html>