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
Q
- The ground reaction force on a body can be represented by a single force
A
Center of pressure
26
Q
- The tuning effect on a body is dependent on which of the following?
Mass of the load; Acceleration of gravity; Moment arm;
A
All of the above
27
Q
- The perpendicular distance of the force form the pount about which the body will turn is called.
A
Moment arm; lever arm
28
Q
- If the force is moved in the direction parallel to the direction of the force, the moment exerted by the force
A
Is unchanged
29
Q
- 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
A
All of the above
30
Q
- ____________ is finding a single force which shall be equal to two or more given forces when acting in given directions.
A
composition of forces
31
Q
- He is the father of the modern engineering mechanics
A
Stephen timoshenko
32
Q
- It is a method of applying mechanics that assumes all object are continuous.
A
Continuum Mechanics
33
Q
- Which of the follwoing is an example of contact force?
A
Air resistance Mechanics
34
Q
- It occurs when an object is moving across a surface.
A
Kinetic friction
35
Q
- Given mu=0.35 between the boject of mass 400 g and the floor, the object will ________ if pulled with a force 3N.
A
Move;Accelerate
36
Q
- 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.
A
The coefficient of static friction is typically greater than the coefficient of kinetic friciton
37
Q
- The equations that apply to bodies moving linearly (that is, one dimension) with uniform accelerations are often referred to as
UVATS; SUVAT; UVAT
A
Either of the above
38
Q
- “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.
A
Second Law
39
Q
- It is also known as quantity of motion
A
Moment
40
Q
- This concept assumes that the substance of the body is distributed throughout and completely fills the space it occupies.
A
Continuum
41
Q
- In fluids, ________ is used to assess to what extent the approximation of continuity can be made.
A
Knudsen Number
42
Q
- It is the time rate of change of any property of a continuum for a specified group of particles of the moving continuum body.
A
Material derivative
43
Q
- Material derivatives is also known as
SUbstatntial derivative; Commoving derivative; Convective derivative
A
All of the above
44
Q
- The vector connecting the postions of a particle in the undeformed and deformed configuration is called the
A
displacement vector
45
Q
95.A_______ is a vector field of all displacement vectors for all particles in the body.
A
displacement field
46
Q
- __________ is the study of the physics of continuous solids with a defined rest shape.
A
Solid Mechanics
47
Q
- It is an experimental method for visualizing and analyzing fluid flow/
A
Partcile Image velocimetry
48
Q
- A Fluid at rest has no.
A
Shear stress
49
Q
- A property of fluids which is the force generated by a fluid in response to a velocity gradient.
A
Viscosity
50
Q
- These equation state that changes in momentum of fluid particles depend only on the external pressure and interval viscous forces acting on the fluid.
A
Navier- strokes Equations
