Engineering mechanics 51-100 Flashcards
1
Q
51.One calculates the work of a force on a rigid body exactly the same as one would calculate the work for a particle
A
Work of a force
2
Q
52.A physical quantity that is completely described by a real number is called
A
Scalar
3
Q
- a convenient means of representing physical quantities that have magnitude and direction
A
vectors
4
Q
- The product of a scalar and a vector is a
A
Vector
5
Q
- it is simply a vector whose magnitude is 1
A
unit vector
6
Q
- It is sometimes called the scalar product.
A
Dot product
7
Q
- To calculate for the force exerted on a charged particle by a magnetic field, _______ is used.
A
Vector product
8
Q
- It is sometimes called the vector product.
A
Cross product
9
Q
- Which of the following statement is false?
The cross product is commutative;The cross product is associative with respect to scalar multiplication.;The cross product is distributive with respect to vector addition.;The angle between two identical vectors placed tail to tail is zero
A
The cross product is commutative
10
Q
- When a force is represented by a vector, the straight line colinear with the vector is called the
A
line of action
11
Q
- A system of forces is ______ if the lines of action of the forces intersect at a point.
A
Concurrent
12
Q
- A system of two forces is __________ if the lines of action of the force lie in a plane.
A
Coplanar; two-dimensonal
13
Q
- Force acting on an object is called a __________ if acts on the volume of the object.
A
Body force
14
Q
- If each point on the object has the same constant velocity, this is referred to as.
A
Steady translation
15
Q
- The moment of a force about a point P is equal to the sum of the moments of its components about P.
A
Varignon’s Theorem
16
Q
- It is measure of the tendency of a force to cause rotation about a line or axis.
A
Moment
17
Q
- A couple is composed of two forces that are
A
Equal, opposite and different lines of action
18
Q
- Which of the following statemens is true about a couple?
A couple does not tend to cause a rotation of an object.; The vector sum of the force couple always has a value.; A couple tends to cause a rotation of an object.; The moment it exerts is not the same about any point.
A
A couple tends to cause a rotation of an object
19
Q
- If an object is on an inclined plane having an angle theta, the component of weight (w) parallel to incline is
A
w sin theta
20
Q
- A type of force acting on a body due to the acceleration of gravity.
A
Load
21
Q
- A type of force acting on a body caused by the friction between the body and the ground.
A
Shear
22
Q
- The unit of force, Newton, us equivalent to
A
kg-m/s^2
23
Q
- When a body is in contact with the ground, the force that is reflected back to the body is called.
A
Ground reaction force
24
Q
- The gravity in the moon is about.
A
1.6 m/s^2
25
75. The ground reaction force on a body can be represented by a single force
Center of pressure
26
76. The tuning effect on a body is dependent on which of the following?
Mass of the load; Acceleration of gravity; Moment arm;
All of the above
27
77. The perpendicular distance of the force form the pount about which the body will turn is called.
Moment arm; lever arm
28
78. If the force is moved in the direction parallel to the direction of the force, the moment exerted by the force
Is unchanged
29
79. The moment of force is zero when?
The applied force is zero; the force is applied at the moment axis.; The line of action of the force is parallel to the axis
All of the above
30
80. ____________ is finding a single force which shall be equal to two or more given forces when acting in given directions.
composition of forces
31
81. He is the father of the modern engineering mechanics
Stephen timoshenko
32
82. It is a method of applying mechanics that assumes all object are continuous.
Continuum Mechanics
33
83. Which of the follwoing is an example of contact force?
Air resistance Mechanics
34
84. It occurs when an object is moving across a surface.
Kinetic friction
35
85. Given mu=0.35 between the boject of mass 400 g and the floor, the object will ________ if pulled with a force 3N.
Move;Accelerate
36
86. Which of the following statements is correct?
The coefficient of static friction is always less than 1; The coefficient of static friction is typically greater than the coefficient of kinetic friciton; The coefficient of kinetic friction is typically greater than the coefficient of static friction; The coefficient of static and kinetic friction are always equal.
The coefficient of static friction is typically greater than the coefficient of kinetic friciton
37
87. The equations that apply to bodies moving linearly (that is, one dimension) with uniform accelerations are often referred to as
UVATS; SUVAT; UVAT
Either of the above
38
88. "Observed from an internal reference frame, the net force on a particle is proportional to the time rate of change of its linear momentum". This is known as Newton's _______ of motion.
Second Law
39
89. It is also known as quantity of motion
Moment
40
90. This concept assumes that the substance of the body is distributed throughout and completely fills the space it occupies.
Continuum
41
91. In fluids, ________ is used to assess to what extent the approximation of continuity can be made.
Knudsen Number
42
92. It is the time rate of change of any property of a continuum for a specified group of particles of the moving continuum body.
Material derivative
43
93. Material derivatives is also known as
SUbstatntial derivative; Commoving derivative; Convective derivative
All of the above
44
94. The vector connecting the postions of a particle in the undeformed and deformed configuration is called the
displacement vector
45
95.A_______ is a vector field of all displacement vectors for all particles in the body.
displacement field
46
96. __________ is the study of the physics of continuous solids with a defined rest shape.
Solid Mechanics
47
97. It is an experimental method for visualizing and analyzing fluid flow/
Partcile Image velocimetry
48
98. A Fluid at rest has no.
Shear stress
49
99. A property of fluids which is the force generated by a fluid in response to a velocity gradient.
Viscosity
50
100. These equation state that changes in momentum of fluid particles depend only on the external pressure and interval viscous forces acting on the fluid.
Navier- strokes Equations
