# PSC 133 Study Guide - Fall 2019, Comprehensive Final Exam Notes - Euclidean Vector, Net Force, Electromagnetic Radiation

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PSC 133

Lecture 1

Physical science is any of the natural sciences dealing with inanimate matter or with energy

as physics and chemistry

Physics is the study of matter, energy, motion and force

Chemistry is the study of matter and its properties

What is matter?

Matter is anything that has mass and volume

Scientific Method

To understand the chemical ad physical properties of matter efficiently and

systematically, we must use the scientific method

1. Everything stars from observation

Ex. Ny observation, there seems to be a relation between temperature and the volume of

a gas

2. We hypothesize that the volume of the gas is proportional to the temperature

Ex. We hypothesize that the volume of the gas is proportional to the temperature

3. We must test this hypothesis through an experiment

The information obtained in the experiment is called experimental data

Experimental data alone does not mean very much

4. We need to build a model (theory) that is consistent with the data

Experimental data seems to lie on a straight line

We can model the data by using the formula for a straight line; y =mx+b

If we use kelvin (k) scale for the temperature, we can find a constant at which another

constant b vanishes

The model reduces to a very simple form v=axt

5. Further experiment

As the model (theory) gets very refined through rigorous further experiments and repeated

modifications, it sometimes come to a point that a majority of scientists accept the theory as

truth (which is dangerous). At this point, this refined model becomes accepted a natural law.

Ex. Charle's law of ideal gas

What is science?

1. Endless search for the truth

2. Work in progress

3. Not perfect

-Richard Feynman (1918-1988)

"In fact everything we know is only some kind of approximation, because we know that we

do not know all the laws as yet."

SI Units

-In science, things are usually measured in standard units called SI Units

-SI Unit is a revised metric system accepted by scientists throughout the world

-SI units consist of seven base units and many derived units (combinations of base units)

Base units:

Mass is in kg

Length is in m

Time is in s

Temperature K

Amount of substance

Mol

Electric current A

Luminous intensity cd

Derived units

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Area is in m squared

Cvolume is in cubic meter

Density is in kg per cubic meter

Velocity Is in m per second

And many moreā¦

Decimal prefixes and scientific (exponential) notations

-Scientific measurements deal with gigantic quantities as well as ultra small quantities

Ex. Approximate mass of the earth is 59800000000000000000000 metric tons

Ex. Mass of an electron is 0.000000000000000000009109 g

-To avoid dealing with numerous zeros *which is cumbersome), scientists employ two

methods to simplify numbers

Scientific notation

Scientific notation consists of a decimal part and an exponential part

Ex. 12345m can be written in scientific notation as: 1.2345x10^4 m

Recall:

10^0=1

10^1=10

10^2=100

10^3=1000

10^-1=1/10=0.1

10^-2=1/100=0.01

10^-3=1/1000=0.001

Practice

10^ax10^b=10^a+b

10^2x10^4=10^6

10^2x10^-4=10^-2

10^a/10^6=10^a-b

10^2/10^4=10^-1

10^2/10^-4=10^6

(10^a)^b=10^axb

(10^2)^3=10^6

1/10^a=10^-a

1/10^5=10^-5

-In formal scientific notation decimals must be moved so that the decimal part is a number

greater than or equal to 1 and it must be less than 10

Ex. 1.2x10^-6 s (correct)

Ex. 12x10^-7 s (wrong)

Ex. 0.12x10^-5 s (wrong)

Technique 1

0.0045x10^-5 = 0.0 4.5x10^-3x10^-5

=4.5x10^-3-5

=4.5x10^-8

Technique 2

-Besides scientific notation, we may avoid excess numbers of zeros by using decimal prefixes

Ex. 2000g can be rewritten as 2kg

Ex. 0.003m can be rewritten as 3mm

Common decimal prefixes

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