Engineering Mechanics 251-291 Flashcards
1
Q
- The term _____ is used when rotating to the center of gravtiy of a weightless figure such as a line, an area or a vloume.
A
Centroid
2
Q
252.The moment of inertia is sometimes called the
A
second moment of area
3
Q
- The term _______ is used to describe another mathematical expression appears and appears must frequently in colummn formulas.
A
Radius gyration
4
Q
- The moment of inertia of an area is defined by the equation?
A
Sp^2dA
5
Q
- The pendulum clock was developed by
A
Huygens
6
Q
- It the geometry of motion.
A
Kinematics
7
Q
- It is the branch of mechanics that relates the force acting on a body to its mass and acceleration.
A
Dynamics
8
Q
- The ______ expresses the relation between the external forces applied to a system of particles and the effective force on each particle of the system.
A
D’alemberts principle
9
Q
- It is defined as the motion of a rigid body in which a straight live passing through any point of the body always remain parallel to its initial position.
A
Translation
10
Q
- The motion of translating body moving in a straight line is called
A
Rectilinear translation
11
Q
- If the path of the translating body is curved, the motion becomes
A
Curve linear translation
12
Q
262.The area under a v-t curve represents the change in
A
displacement
13
Q
- The area under an a-t curve represents the change in
A
Acceleration
14
Q
- When the principle of the motion of the center of gravity is
A
applied to rectilinear translation we obtain
15
Q
265.The normal component of acceleration is expressed by
A
an= v^2/r
16
Q
- It is defined as that motion of rigid body in which the particles move in a circular paths with their center on a fixed straight line.
A
Rotation
17
Q
- ___________ is measured in radians by the angular distance swept through by any radians of or line in the rotatin body
A
angular displacement
18
Q
- It is defined as the motion of rigid body in which all particles in the body remain at a constant distance from a fixed reference plane.
A
Plane motion
19
Q
- The expression (w/2g)v^2 is defined as
A
Resultant work
20
Q
- The epxression S^-8osumationX ds is defined as
A
Resultant work
21
Q
- It is a motion which repaets itself after a define internal of time
A
vibration
22
Q
- The maximum displacement of the body from its equilibrium position is known as the ______ of the vibration.
A
Amplitude
23
Q
- Each repetition of the motion is called a
A
cycle
24
Q
- The _________ of the vibration is the reciprocal of the period and is measured in cycles per second.
A
frequency
25
Q
- The time required to complete one oscillation backward and forward is calledd the _____ of the motion.
A
Period
26
Q
- The condition existing when the impressed frequency is equal to the natural frequency is known as
A
resonance
27
Q
- The speed of rotation at which resonance occurs is called.
A
critical speed
28
Q
- The a = w^2s is the mathematical description for
A
Simple harmonic motion
29
Q
- ________ is the rate at which work is done on a body.
A
Power
30
Q
- The _______ is a traditional unit equivalent to 550 ft-lb of work per sec. or 33,000 ft-lb of work per min.
A
Horse power
31
Q
- It is the ratio of power output to power input
A
Efficiency
32
Q
- It is defined as that which changes, or tends to change, the state of motion of a body.
A
Force
33
Q
- An axis passing through the centroid of an area is known as a
A
centroidal axis
34
Q
- It is defined as the time rate of change of displacement.
A
Velocity
35
Q
- It is defined as the time rate of change of velocity
A
Acceleration
36
Q
- The ___________ is a force that results from the attraction between the mass of the body and the mass of the earth.
A
density
37
Q
- The line joining the center of gravity and thecenter of rotation will be called
A
N axis
38
Q
- The line through the center of rotaiton perpendicular to N will be called
A
T axis
39
Q
- The axis of rotation will be called the
A
Z axis
40
Q
- The _________ are called the normal and tangential axes since they are respectively normal and tangent ot hte path of the center of gravity.
A
Rotatin axes
41
Q
- A ______ is defined as particle at the end of weightless cord where is allowed to vibrate in a vertical arc of a circle under the influence of gravity and the tension in the cord.
A
