College Physics
Chapter 1:
Introduction
Chapter 1
INTRODUCTION
Conceptual Questions
1.
Knowledge of physics is important for a full understanding of many scientific disciplines, such as chemistry, biology,
and geology. Furthermore, much of our current technology can only be understood with knowledge of the underlying
laws of physics. In the search for more efficient and environmentally safe sources of energy, for example, physics is
essential. Also, many study physics for the sense of fulfillment that comes with learning about the world we inhabit.
2.
Without precise definitions of words for scientific use, unambiguous communication of findings and ideas would be
impossible.
3.
Even when simplified models do not exactly match real conditions, they can still provide insight into the features of a
physical system. Often a problem would become too complicated if one attempted to match the real conditions
exactly, and an approximation can yield a result that is close enough to the exact one to still be useful.
4.
(a)
3
(b)
9
5.
Scientific notation eliminates the need to write many zeros in very large or small numbers. Also, the appropriate
number of significant digits is unambiguous when written this way.
6.
In scientific notation the decimal point is placed after the first (leftmost) numeral. The number of digits written
equals the number of significant figures.
7.
Not all of the significant digits are precisely known. The least significant digit (rightmost) is an estimate and is less
precisely known than the others.
8.
It is important to list the correct number of significant figures so that we can indicate how precisely a quantity is
known and not mislead the reader by writing digits that are not at all known to be correct.
9.
The kilogram, meter, and second are three of the base units used in the SI system.
10.
The SI system uses a welldefined set of internationally agreed upon standard units and makes measurements in
terms of these units and their powers of ten. The U.S. Customary system contains units that are primarily of historical
origin and are not based upon powers of ten. As a result of this international acceptance and the ease of manipulation
that comes from dealing with powers of ten, scientists around the world prefer to use the SI system.
11.
Fathoms, kilometers, miles, and inches are units with dimensions of length. Grams and kilograms are units with
dimensions of mass. Years, months, and seconds are units with dimensions of time.
12.
The first step toward successfully solving almost any physics problem is to thoroughly read the question and obtain a
precise understanding of the scenario. The second step is to visualize the problem, often making a quick sketch to
outline the details of the situation and the known parameters.
13.
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 Spring '11
 DanielHale
 Physics, Current, Force, Work

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