intro to physical science and measurements

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CHAPTER 1INTRODUCTION

TO PHYSICAL SCIENCE

+SCIENCEsystematized or organized body of knowledge based on observation, experimentation and study.

comes from the Latin word Scientia - knowledge or knowing

+ BRANCHES OF SCIENCE

Biological SciencePhysical ScienceSocial Science

+BIOLOGICAL SCIENCEdeals with the study of living things

ex. Biology, Botany, Zoology, Ornithology

+ SOCIAL SCIENCE

Study of human behaviour and societies

Ex. History, Economics, Political Science

+ PHYSICAL SCIENCE

deals with the study of non-living things, their composition, nature, characteristics, the changes they have undergone and the factors affecting these changes

+ BRANCHES OF PHYSICAL SCIENCE

Chemistry- the study of “matter”- its composition, properties, structure and the changes it undergoes.


Physics- the science of matter and energy and their interaction with each other.


Astronomy- study of the universe and the heavenly bodies.


Geology- deals with the composition of Earth materials, Earth structures, and Earth processes


Meteorology- study of the atmosphere and how processes in the atmosphere determines Earth’s weather and climate

+

CHAPTER 2MEASUREMENT

+MEASUREMENTCollection of quantitative

dataMade by comparing an

unknown quantity with a standard unit

Example: The length of a piece of string can be measured by comparing the string against a meter stick.

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+Every measurement is composed of a number and a unit.

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+ SYSTEMS OF MEASUREMENT

ENGLISH SYSTEM- most commonly used in the US.

Disadvantage: units are not systematically related to each other and require memorization.

METRIC (SI)- used by the scientist around the world. Adopted from the French name Le Systeme Internationale d’ Unites

+ENGLISH SYSTEM UNITS

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+SI PREFIXES

+

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+ LENGTH Measurement of anything from end to end How long an objects is The basis of length units for the metric system

is the meter.1 inch = 2.54 centimeters = 25.4

millimeters1 foot = 30.48 centimeters

1 yard = 0.91 meters1 mile = 1.6 kilometers

1 millimeter = 0.04 inches1 centimeter = .39 inches = 0.0325 feet

1 meter = 3.28 feet1 kilometer = 0.62 miles

+MASS AND WEIGHT Mass and weight are not the same thing. Although we

often use the interchangeably, each one has a specific definition and usage.

Mass- measure of the amount of matter in an object. The mass of an object is independent of its location. The basic unit form mass is kilogram (kg) .

Weight- force of attraction between the object and the earth’s gravity. The weight of an object can vary from place to place and changes with its location on the Earth.

+DEVICES USED IN

MEASURING

UNITS CONVERSION

+ TIMEInterval between two occurrences. The

basic unit for time is second.

• 1 minute (60 seconds)• 1 hour (60 minutes, or 3,600

seconds)• 1 day (24 hours, or 86,400

seconds)• 1 week (7 days, or 604,800

seconds)• 1 month (28-31 days, or

2,419,200-2,678.400 seconds)• 1 year (about 365.25 days, or

about 31,557,600 seconds)

+ TEMPERATURE Measure of how hot or cold an object is. The basic unit

for temperature is Kelvin.

+ To convert from Celsius to Fahrenheit

To convert from Fahrenheit to CelsiusoC= oF – 32/ 1.8

To convert from Celsius to KelvinK= oC + 273

To convert from Kelvin to CelsiusoC= K - 273

oF= 1.8 (oC) + 32

+Reading temperature in a thermometer

Answers:

+

Kilo(1000)

Hecto(100)

Deca(10)

Base Unitsmetergramliter

deci(1/10)

centi(1/100)

milli(1/1000)

An easy way to move within the metric system is by moving the decimal point one place for each “step” desiredExample: change meters to centimeters

1 meter = 10 decimeters = 100 centimetersor1.00 meter = 10.0 decimeters = 100. centimeters

CONVERTING UNITS: METRIC TO METRIC

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Kilo(1000)

Hecto(100)

Deca(10)


deci(1/10)

centi(1/100)

milli(1/1000)

Now let’s try this example from meters to kilometers:16093 meters = 1609.3 decameters = 160.93 hectometers = 16.093

kilometers

So for every “step” from the base unit to kilo, we moved the decimal 1 place to the left (the same direction as in the diagram below)

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Kilo(1000)

Hecto(100)

Deca(10)


deci(1/10)

centi(1/100)

milli(1/1000)

If you move to the left in the diagram, move the decimal to the left

If you move to the right in the diagram, move the decimal to the right

+

Kilo(1000)

Hecto(100)

Deca(10)


deci(1/10)

centi(1/100)

milli(1/1000)

Now let’s start from centimeters and convert to kilometers

400000 centimeters = ______kilometers

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Kilo(1000)

Hecto(100)

Deca(10)


deci(1/10)

centi(1/100)

milli(1/1000)

Kilo(1000)

Hecto(100)

Deca(10)


deci(1/10)

centi(1/100)

milli(1/1000)

Now let’s start from meters and convert to centimeters

5 meters = _____ centimeters

• Now let’s start from kilometers and convert to meters

.3 kilometers = ______ meters

+

A conversion factor is a term that converts a quantity in one unit to a quantity in another unit.

Factor-label method is the process of using conversion factors to convert a quantity in one unit to a quantity in another unit.

CONVERTING UNITS: USING THE FACTOR-LABEL METHOD

+ The conversion factor must relate the two quantities in questions.

The conversion factor must cancel out the unwanted unit.

+Let’s say we want to convert 130 lb to kilograms.130 lb X conversion factor= ____ kg

Two possible conversion factors: 2.21 lb or 1 kg__1 kg 2.21 lb

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130 lb x 1 kg__ = 59 kg 2.21 lb

Pound (lb) must be the denominator to cancel the unwanted unit (lb) in the original quantity.

+TRY…

a. 32 inches to centimeterb. 6250 ft to kmc. 25 L to dL

+DERIVED UNITS

+AREAamount of two-dimensional space taken

up by an objectthe size of a surfaceArea of rectangle(A) = length(l) x

width(w)Area of circle (A)= π × r2

+ This table lists different area units, and values that will help you change units of area measurements:

+ VOLUME

1 L = 10 dL1 L = 1000 mL1 000 L = 1 m3

1 dL = 100 mL1 mL = 1 cm3 = 1 cc

1 cc = .001 L1 L= 1 000 cc

+ DENSITY Mass per unit volume Units: g/cc , g/cm3 , g/mL Formula:

+Sample Problem: Calculating Density

A piece of beeswax with a volume of 8.50 cm3 is found to have a mass of 8.06 g. What is the density of the beeswax?

+Using Density to find Volume

Cobalt is a hard magnetic metal that resembles iron in appearance. It has a density of 8.90 g/cm3 . What volume would 17.8 g of cobalt have?

+

Using Density to find Mass

Mass is the mass of 19.9 cm3 of coal that has a density of 1.50 g/cm3?

+ SCIENTIFIC NOTATIONScientific notation is a way of expressing Scientific notation is a way of expressing

really big numbers or really small numbers.really big numbers or really small numbers.Scientific Notation always has two parts:

N is the coefficient ( A number between 1 and N is the coefficient ( A number between 1 and 9.9999…)9.9999…)

X is an exponent, which can be any positive or X is an exponent, which can be any positive or negative whole number.negative whole number.

N x 10N x 10xx

+Writing Scientific NotationPlace the decimal point so that there is Place the decimal point so that there is oneone non-zero digit to the left of the non-zero digit to the left of the decimal point.decimal point.

Count the number of decimal places Count the number of decimal places the decimal point has “moved” from the decimal point has “moved” from the original number. This will be the the original number. This will be the exponent on the 10.exponent on the 10.

If the original number was less than 1, If the original number was less than 1, then the exponent is negative. If the then the exponent is negative. If the original number was greater than 1, original number was greater than 1, then the exponent is positive.then the exponent is positive.

+TRY…Express in Scientific Notation1. 2302. 14 100 0003. 0.000264. 0.0000006985. 0.089

+Change Scientific Notation back to Standard Form Simply move the decimal point to the right for positive Simply move the decimal point to the right for positive

exponent 10. exponent 10. Move the decimal point to the left for negative exponent Move the decimal point to the left for negative exponent

10.10.

(Use zeros to fill in places.)(Use zeros to fill in places.) Example:Example: Given: 5.093 x 10Given: 5.093 x 1066

Move: 6 places to the right (positive)Move: 6 places to the right (positive) Answer: 5,093,000Answer: 5,093,000

+TRY…Express in Standard Notation1. 1.5 x 103

2. 3.4 x 108

3. 6.86 x 10-6

4. 5.822 x 10-5

5. 4.02 x 1010

+OPERATIONS WITH SCIENTIFIC NOTATION

+TRY…

+OPERATIONS WITH SCIENTIFIC NOTATION

+TRY…

+SIGNIFICANT FIGURESNumber of significant digits that implies the accuracy of measurement

+Determining the number of significant figuresRules:1.All nonzero digits are significant.

25 L – 2 significant figures65.2 kg – 3 significant

figures

2. Zeros between two nonzero digits are significant.

29.05 g – 4 significant figures1.0087 mL – 5 significant

figures

3. Leading zeros are not significant.

0.000000872 miles – 3 significant figures

0.03 mg – 1 significant figure

4. Trailing zeros in a number containing a decimal point are significant

25.70 lbs – 4 significant figures708.00 km – 5 significant

figures

5. The trailing zeros in which decimal point is not given/placed indicated that zero/s is/are not significant.

1, 245, 500 m – 5 significant figures

5280 ft – 3 significant figures

+TRY…How many significant figures do each number contain?1.34.08 L2.0.0054 mm3.260.00 g4.550 miles5.0.008 mL

6. 3.7500 cm7. 1,200,000

miles8. 23.45 lbs9. 1, 000, 0034

ft10. 0.001003

mm

+RULES FOR USING SIGNIFICANT FIGURES IN CALCULATIONS

When adding or subtracting significant figures, the answer should have the same number of decimal places as the original number with the fewest decimal places.

+Example: Baby Zayn weighed 3.6 kg at birth

and 10.11 kg on his first birthday. How much weight did he gain in his first year of life.

10.11 kg - 3.6 kg

6. 51 kg •The answer can have only one digit after the decimal point. •Round 6.51 to 6.5•Baby Zayn gained 6.5 kg during his first year of life.

+RULES FOR USING SIGNIFICANT FIGURES IN CALCULATIONS

When multiplying or dividing significant figures, the answer should have the same number of significant figures as the original number with the fewest significant figures.

+TRY…Solve the following and write you answer in correct significant figure.1. 8.937 + 8.930=2. 0.00015 x 54.6=3. 847.89 - 847.73=4. 3.2 / 1.60 =5. 7.1 x 10=

intro to physical science and measurements

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