QUIZ 1 SCIENCE

Science

– systematic body of knowledge

– from Latin scientia meaning “knowledge”

– refers to the body of knowledge that entails unbiased observations and systematic experimentation about the universe and its phenomena

– involves the pursuit and process of seeking general truths and applying knowledge about our universe

Pure science

focused on the theories or pursuing knowledge for its own sake (e.g. astronomy)

Applied science

ways to use this knowledge to come up with practical solutions (e.g. engineering) 

3 areas of science

1. Physical

2. Life

3. Social

Physical

- nonliving things
- physics, chemistry, geology

Life

- living things

- biology, environmental science, zoology, botany

Social

- social and cultural aspects of human behavior

- psychology, sociology

Physics

– from the greek ta physika which means “the natural things”

– study of the fundamental structures and interactions on the physical universe from the nano world to the macro cosmos

– physics is everything

- an experimental science

Classical physics

first version of physics up to the 18th – 19th centuries

Acoustics

physical aspects of sound waves

Electromagnetism

charges (+ / –) at rest or in motion, their effects, and relationship with magnetism

Optics

physical aspect of light and other electromagnetic radiation

Thermodynamics

nature of heat, the movement and modes of transfer

Mechanics

motion of objects, its causes and effects

Modern physics

20 to the 21st Centuries
    – nature and behavior of matter under extreme
      conditions 

                                   ○  quantum mechanics

                                  ○  astrophysics

                                  ○  particle physics

                                  ○  condensed matter physics

                                  ○  nuclear mechanics

                                  ○  plasma mechanics

Interaction of physics in other fields

– physics in medicine
– physics in ICT – physics in transportation

Why study physics?

– thinking logically and analytically

– solving problems

– making simplified assumptions

– constructing masthematical models

Mathematical tools used for measuring

Mass, length, volume

Tools used for measuring mass

Top loading balance, triple beam balance, analytical balance

Tools used for measuring length

Ruler, vernier caliper, measuring tape

Tools used for measuring volume

Beaker, graduated cylinder, Erlenmeyer flash

Tools for measuring temperature

Lab thermometer

Celsius to Fahrenheit

Fahrenheit = 9/5Celsius + 32

Fahrenheit to Celsius

Celsius = 5/9 (Fahrenheit - 32)

Celsius to kelvin

Kelvin = Celsius + 273

Significant figures

– also known as Significant Digits, S.F., Sig. Fi.

– all certain digits + 1 uncertain digit

75.648 has five significant figures, 75.64 are the certain digits and 8 is the uncertain digit.

Sensitivity of equipment

– “How many decimal places can it read?”
– The higher the sensitivity, the more significant figures
– The last digit displayed that fluctuates is the uncertain digit

Rules for significant figures

1. All nonzero digits of a measurement are significant
(e.g. 283.47)

2. Zeros occurring between significant digits are significant
– “trapped zeros”
(e.g. 56.06)

3. All final zeros past the decimal point are significant
– “trailing zeros”
(e.g. 73.00)

4. Zeros used as placeholders are not significant
– “leading zeros”

(e.g. 0.09)

5. Trailing zeros are ambiguous; they can be significant/not significant
(e.g. 930,000)
– can be 2 sf or 6 sf

All non zero digits are significant

Rule #1: example is 273.15 = 5 sigfigs

Zeros occurring between significant digits are significant

Rule #2: trapped zeros, ex: 56.06 = 4 sigfigs

All final zeroes past the decimal point are significant

– “trailing zeros”

(e.g. 73.00)

Zeros used as placeholders are not significant

– “leading zeros”

(e.g. 0.09)

Trailing zeros are ambiguous, usually are not significant

(e.g. 930,000)
– can be 2 sf or 6 sf

ALWAYS CONVERT!!

Addition and subtraction rule

As many decimal places as the measurement with the LEAST decimal places

Multiplication and division

– as many significant digits as the measurement with the least

Rounding number rules

0-4: digits are not kept altered

  – 3.14 = 3.14

5-9: digits are rounded up by 1

  – 3.15 = 3.2

Scientific notation

– a convenient method of expressing very large or very small numbers

– also indicates number of SF

Scientific notation rule for addition and subtraction

Exponents must be the same for addition (ex: 1.4×10²) + (2.30×10³) → must convert to the LOWEST exponent

Scientific notation in multiplication and division

Numerical parts (without exponent), are simply multiplied while the exponents are added (for multiplication) or subtracted (for division)

Accuracy

measure of how close a measurement is to the correct, accepted, true, theoretical value of the quantity being measured

Precision

measure of how close a series of measurements are to each other; precise measurements are highly reproducible

Physics as experimental science

– because theories are based on observations and careful

  experiments, careful measurements are very important

  in physics, but no measurement is perfect

Systemic error

errors that have a clear cause that can be eliminated and/or resolved by future experiments

Types of systemic error

Instrumental and environmental

Instrumental error (S)

improper calibration

Environmental error (S)

for example, phone near a Geiger counter

Observational error (S)

for example, wrong meniscus view

Random error

errors that often have no source or cause

Types of random error

Observational and environmental errors (R)

Observational error (R)

for example, fluctuating numbers when it comes to instrument even if it’s calibrated

Environmental error (R)

for example, temperature change

What affects a persons ability to do measurements

1. Instrument

2. Your ability to read and interpret what the instrument tells you

Percent difference

– used to compare two

or more values to each other

– looks at how different the

values are as a percentage

of their average value

Percent error

– used to compare a measured

value to an accepted, known, or

theoretical value

– difference between measured

and theoretical value as a percentage

of the theoretical value

– small percent errors are acceptable;

it means they are closer to the

true value (1% to 5%)

Measurement

– process of comparing an unknown quantity (measurand) to a known value (standard)

SI Units

– most widely used set of standard values
– stands for (English) International System of Units
– stands for (French) Système International d’Unités

3 kinds of numbers

Counted, defined and measured

Counted

exact, whole number

Defined

involve exact numbers but are not always whole number

Measured

come from reading measuring devices, never exact

Base quantities

quantities which do not depend on other quantities and can exist by themselves

Derived quantities

combination of more than one quantity (and depend on other quantities)

Dimensional analysis

– converting from one dimension to another