This preview shows pages 1–3. Sign up to view the full content.
Chapter 1 – Physical Concepts
Important Terms
Scientific notation
provides a simple way to represent both large and small
numbers with equal ease and a convenient basis for
computations with such numbers, for conversions
between metric measures, and for conversions of
numbers to logarithms; involves translating any
numbing into the product of a coefficient multiplied by
some power of 10
Laws of exponents rules governing the computations of numbers represented in
scientific notation
Magnitude
size
Vectorial quantities quantities that have both magnitude and direction
Vectors
quantities that have both magnitude and direction
Scalar quantities
quantities that are characterized by magnitude alone
Scalars
quantities that are characterized by magnitude alone
Units of measure
required to facilitate the universal communication of a given
quantity
Dimensions dimensions of physical quantities cannot be combined in just any
manner, their dimensions must be considered; length,
time, and mass are dimensions of all physical
quantities encountered in mechanics and acoustics
Length
MKS unit – meter; CGS unit – centimeter; determined by comparing
the unknown quantity to a standard of measure, such
as the meter; scalar quantity; represented by the letter
L
Time
unit – second; scalar quantity; represented by the letter T
Mass property of all matter; any given substance will have the same mass
regardless of its location in the universe; a substance
may be weightless, but it cannot be massless; scalar
quantity; has the dimension M; measured by using a
balance and comparing the unknown quantity to a
standard measure; unit – gram
This preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentDistance
spatial separation between two points; dimension is one of length;
denoted by L; scalar quantity
Displacement
when an object moves from one point to another it has been
displaced; change in position, both magnitude and
direction; vector quantity; measured in meters
Area
derived quantity involving the dimension of length; measured in units of
square meters, m
2
in the MKS system and cm
2
in the
CGS system; L*L=L
2
or the area
Velocity
derived quantity that involved combining the dimensions of length
and time; rate at which an object moves from one
point to another; vector
Acceleration instanttoinstant changes in velocity; vector; MKS unit – m/s
2
; CGS
unit – cm/s
2
Force derived quantity; requisite to an understanding of work, energy, and
power; measure of sound magnitude—sound
pressure and acoustic intensity—are intimately
related to force; may be defined as a push or a pull;
equal to mass times acceleration; F=ma
Newton’s laws
1. An object at rest tends to remain at rest; an object in
motion tends to maintain the magnitude and direction
of its velocity (unless acted upon by an extraneous
force)
2. The net force acting upon an object in motion is equal to the product of
its mass and the acceleration imparted to it by the
force (in the same direction as the force)
3. The forces of two bodies on each other are always equal and directly
This is the end of the preview. Sign up
to
access the rest of the document.
 Spring '11
 Durrant

Click to edit the document details