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
275. The time required to complete one oscillation backward and forward is calledd the _____ of the motion.
Period
26
276. The condition existing when the impressed frequency is equal to the natural frequency is known as
resonance
27
277. The speed of rotation at which resonance occurs is called.
critical speed
28
278. The a = w^2s is the mathematical description for
Simple harmonic motion
29
279. ________ is the rate at which work is done on a body.
Power
30
280. The _______ is a traditional unit equivalent to 550 ft-lb of work per sec. or 33,000 ft-lb of work per min.
Horse power
31
281. It is the ratio of power output to power input
Efficiency
32
282. It is defined as that which changes, or tends to change, the state of motion of a body.
Force
33
283. An axis passing through the centroid of an area is known as a
centroidal axis
34
284. It is defined as the time rate of change of displacement.
Velocity
35
285. It is defined as the time rate of change of velocity
Acceleration
36
286. The ___________ is a force that results from the attraction between the mass of the body and the mass of the earth.
density
37
287. The line joining the center of gravity and thecenter of rotation will be called
N axis
38
288. The line through the center of rotaiton perpendicular to N will be called
T axis
39
289. The axis of rotation will be called the
Z axis
40
290. The _________ are called the normal and tangential axes since they are respectively normal and tangent ot hte path of the center of gravity.
Rotatin axes
41
291. 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.
