Physics (Midterms - Concepts) Flashcards
1
Q
describes the relationship between the motion of objects in our everyday world and the forces acting on them
A
dynamics
2
Q
Language of Dynamics
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Force and Mass
3
Q
the measure of interaction between two objects (pull or push). It is a vector quantity - it has a magnitude and direction
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force
4
Q
the measure of how difficult it is to change object’s velocity (sluggishness or inertia of the object)
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mass
5
Q
may be a contact force or field force
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forces
6
Q
it result from physical contact between two objects
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contact forces
7
Q
it act between disconnected objects and it is also called as “action at a distance”
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field forces
8
Q
Forces
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gravitational force
archimedes force
friction force
tension force
spring force
normal force
9
Q
a resultant force acting on object
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net force
10
Q
an object at rest tends to stay at rest and an object in motion tends to stay in motion with the same speed and in the same direction unless acted upon by an unbalanced force
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newton’s first law
11
Q
it is defined as the vector sum of all the external forces exerted on the object
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net force
12
Q
is a property of objects to resist changes in motion
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inertia
13
Q
is a measure of the amount of inertia
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mass
14
Q
is a measure of the resistance of an objects to changes in its velocity
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mass
15
Q
is an inherent property of an object
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mass
16
Q
the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass
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newton’s second law
17
Q
also measured in lbs, is a force (mass x acceleration)
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weight
18
Q
the magnitude of the gravitational force acting on an object of mass m near the earth’s surface is called the
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weight
19
Q
it can also be found from the law of universal gravitation
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g
20
Q
it has a unit of N
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weight
21
Q
force from a solid surface which keeps object from falling through
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normal force
22
Q
its direction is always perpendicular to the surface
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normal force
23
Q
it direction is pointing downward
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gravitational force
24
Q
a taut rope exerts forces on whatever holds its ends
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tension force
25
its direction is always along the cord (rope, cable, string,...) and away from the object
tension force
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if object 1 and object 2 interact, the force exerted by object 1 on object 2 is equal in magnitude but opposite in direction to the force exerted by object 2 on object 1
newton's third law
27
either force can be the action or reaction force
newton's third law
28
the most important step in solving problems involving Newton's laws
free body diagram
29
objects that are either at rest or moving with constant velocity are said to be in equilirbium
objects in equilibrium
30
if an object that can be modeled as a particle experiences an acceleration, there must be a non-zero net force acting on it
accelerating objects
31
4 basic quantities in kinematics
displacement
velocity
time
acceleration
32
any motion involves three concepts
displacement
velocity
acceleration
33
it can be defined as the change of position over time
motion
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is a change of position in time
displacement
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it is a vector quantity. it has both magnitude and direction and it has units of length in meters
displacement
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rate of change of position
velocity
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it is a vector quantity. it has both magnitude and direction. it has a length/time in meter per second1
velocity
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is the slope of the line segment between end points on a graph
average velocity
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total distance over time interval
average speed
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it means "at some given instant"
instantaneous
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it indicated what is happening at every point of time
instantaneous velocity
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is the special case of constant velocity
uniform velocity
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it means "an acceleration is present"
changing velocity or non-uniform
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rate of change of velocity
acceleration
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is the slope f the line connecting the initial and final velocities on a velocity-time graph
average acceleration
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object moving along a curved path with constant speed
circular motion
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is one type of 2D motion under constant acceleration
projectile motion
48
is the study of the basic components of the universe and their interactions
physics
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are used in many practical applications, including construction
principles of physics
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it is very useful during the process of understanding phenomena
models
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is detailed and can give testable predictions
theory
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a brief description of how nature behaves in a broad set of circumtances
law
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is similar to a law, but applies to a narrower range of phenomena
principle
54
is the internationally accepted system of units for measurement in all of the sciences, including physics
SI, or metric system of units
55
is defined as a ratio of units that is equal to 1
conversion factor
56
are the base units that make it up: they are generally written using square brackets
dimensions of a quantity
57
is the checking of dimensions of all quantities in an equation to ensure that those which are added, subtracted, or equated have the same dimensions
dimensional analysis
58
3 factors that determine the effectiveness of the force in opening the door:
the magnitude of the force
the position of the application of the force
the angle at which the force is applied
59
is the tendency of a force to rotate an object about some axis. it is a vector quantity
torque
60
it is also known as "Moments of a Force"
torque
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is the perpendicular distance from the axis of rotation to a line drawn along the direction of the force
moment arm, d
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are diagrams used to show the relative magnitude and direction of all forces acting upon an object in a given situation
free-body diagrams
63
types of forces
applied force
gravity force
normal force
friction force
air resistance force
tension force
64
is a force that is applied to an object by a person or another object
applied force
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also known as weight, is the force with which the earth, moon, or other massively large object attracts another objects towards itself
gravity force
66
is the support force exerted upon an object that is in contact with another stable object
normal force
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is the force exerted by a surface as an object moves across it or makes an effort to move across it
friction force
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There are at least two types of friction force
sliding friction
static friction
69
is a special type of frictional force that acts upon objects as they travel through the air
air resistance force
70
is the force that is transmitted through a string, rope, cable or wire when it is pulled tight by forces acting from opposite ends
tension force
71
This is the force system in which lines of action of individual forces lie in the same plane but act at different points of applications.
non-concurrent force system
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Lines of action of individual forces are parallel to each other
parallel force system
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Lines of action of the forces are not parallel to each other
non-parallel force system
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is the tendency of a force to make a rigid body to rotate about an axis. This is a vector quantity having both magnitude and direction.
moment
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rotational tendency
moment
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This is the axis about which rotational tendency is determined. It is perpendicular to the plane comprising moment arm and line of action of the force
moment axis
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This is the position of axis on co- planar system.
moment center
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Perpendicular distance from the line of action of the force to moment center.
moment arm
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it is computed as the product of the force and the perpendicular distance from the line of action to the point about which moment is computed
magnitude of moment
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is a system of forces whose magnitude of the resultant is zero.
couple
81
is composed of two equal forces that are parallel to each other and acting in opposite direction.
couple
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A couple is completely defined by following elements:
The magnitude of its moment
The plane in which it acts defined by the direction of the normal to the plane.
The direction of rotation in the plane that is the sense of the couple.
83
is a vector quantity having the direction normal to the plane in which it acts.
moment of a couple
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The plane in which the two forces forming a couple lie
plane of the couple
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the distance between their line of action
arm of the couple
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types of loads on beams
Concentrated Loads
Uniformly distributed load
Uniformly varying load
87
This is the load acting for very small length of the beam.
Concentrated Loads
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Also known as point load
Concentrated Loads
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This is the load acting for a considerable length of the beam with same intensity of w kN/m throughout its spread.
Uniformly distributed load
90
This load acts for a considerable length of the beam with intensity varying linearly from ‘0’ at one end to w kN/m to the other representing a triangular distribution
Uniformly varying load
91
is the physical science concerned with the behavior of bodies that are acted upon by forces
Mechanics
92
is the study which deals with the condition of bodies in equilibrium subjected to external forces.
Statics
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is also a branch of mechanics in which the forces and their effects on the bodies in motion are studied
Dynamics
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Dynamics is sub-divided into two parts
Kinematics
Kinetics
95
deals with the geometry of motion of bodies without and application of external forces.
Kinematics
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deals with the motion of bodies with the application of external forces.
Kinetic
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It is defined as a definite amount of matter the parts of which are fixed in position relative to one another under the application of load.
Rigid Body
98
It is that agent which causes or tends to cause, changes or tends to change the state of rest or of motion of a mass.
force
99
A force is fully defined only when the following four characteristics are known:
Magnitude
Direction
Point of application
Sense
100
consists of forces that lie in the same plane.
coplanar force system
101
are commonly encountered in two-dimensional problems and are often analyzed using methods such as vector addition or graphical techniques like the method of polygons.
Coplanar force systems
102
the lines of action of the forces do not intersect at a single point
non-concurrent force system
103
all the forces have their lines of action intersecting at a single point.
concurrent force system
104
If two forces acting at a point are represented in magnitude and direction by the two adjacent sides of a parallelogram, then the resultant of these two forces is represented in magnitude and direction by the diagonal of the parallelogram passing through the same point.
Parallelogram law of forces
105
If two forces acting at a point can be represented both in magnitude and direction, by the two sides of a triangle taken in tip to tail order, the third side of the triangle represents both in magnitude and direction the resultant force F, the sense of the same is defined by its tail at the tail of the first force and its tip at the tip of the second force’.
Triangle law of forces
106
is the effect of a force in a certain direction. A force can be split into infinite number of components along infinite directions.
Component of a force
107
is any quantity in physics that has MAGNITUDE ONLY
scalar quantity
108
is any quantity in physics that has BOTH MAGNITUDE and DIRECTION
vector quantity
109
are represented by drawing arrows
vectors
110
Aligning vectors head to tail and then drawing the resultant from the tail of the first to the head of the last
graphical method
