Physics Unit 0

Physics: Study of fundamental law of nature (motion, forces, energy, matter, heat, sound, and light)

Areas in Physics

Mechanics: the effects of forces on material objects

Thermodynamics; Behavior of large number of particles as they relate to heat and temperature

Electromagnetism: The relationship between changes, currents, and electromagnetic field

Relativity: The theory that describes particles moving at any speed and connects space and time

Quantum Physics: The behavior of particles moving at the submicroscopic (too little to be seen by ordinary microscope) and microscopic level

Vibration/Motion: Repetitive motion

Scientific Method: The systematic approach that scientists use to learn about the laws of nature

STEPS!

  1. state problem: make observation + ask question why?

  2. research: find bg info about the problem

  3. Form hypothesis: what explains problem based on research

  4. Testing: create experiment to test hypothesis (use constant + variables)

    1. Experiment: controlled test of a hypothesis

    2. Constant: Factors that don’t change

    3. Variables- Independent(controlled factor) and Dependent(changes because of independent)

      * Use 1 independent at a time

  5. Analyze data: organize data, put in charts/graphs and find patterns

    • Scientists often GRAPH the results of experiments because relationships/patterns are easier to detect than in data table

      *3 types of graphs

      • Line Graph: graph that’s used when dependent variable changes bc of change in independent variable (Time is “INDEPENDENT” variable, plot in x-axis, you should use line graph)

      • Bar Graph: Graph used when info gathered by COUNTING + COMPARING

      • Pie or Circle: Graph used to show how some fixed quantity if broken down into parts (The circle is the whole, while the slices/pieces are the parts expressed in %.)

      • Linearization of the data; relationship isn’t linear but can be graphed so it has straight line

  6. make conclusion: statement that supports data

Theory: Detailed explanation about an aspect of nature from the tested hypothesis

Scientific law: Laws of nature (observation that always happen)

*if new observation disagrees with the theory, the theory is changed/ignored →it a break through!

Technology: Scientific discoveries are used to solve daily problems/enhance quality of living/meet human needs

*Science and tech depend on each other

Physics uses mathematics as language and is a science of measurement

Unit 2 - Measurements

Standard: exact quality that people agree to use for comparison, when all measurements used by same standard-easier to compare

  • ex. meter stick is used by everyone

Si System: The international system, which is based on metric system

  • everything in Si System has base unit and symbol

  • 7 main unit!!!! everything else can be derived from the 7

LENGTH: Meter (M)

MASS: Kilograms (Kg) in physics, but normally grams

TIME: Seconds (S)

ELECTRIC CURRENT: Ampere (A/amp)

TEMPERATURE: Kelvin (K) and celsius(c )

AMOUNT OF SUBSTANCE: Mole (Mol)

INTENSITY OF LIGHT: Candel (col)

VOLUME: Meter³ (M³)

Common Si prefixes

Giga - (G) - 10^9

Mega - (M) - 10^6

Kilo - (K) - 10³

Hecta - (H) - 10²

Deka - (Da) - 10^1

Base

Deci - (d) - 10^-1

Centi - (c )- 10^-2

Miili - (m) - 10^-3

Micro - (μ) - 10^-6

Nano - (n) - 10^-9

Pico - (p) -10^-12

great mighty king Henry died by drinking chocolate milk, might need picnic

* Move up for smaller units to larger aka LEFT

*Move down for larger units to smaller aka RIGHT

Random formula- Multiply by 1000/3600 to convert km/hr to m/s

Dimensional analyses: mathematical way to convert more complex units using math

Scientific notation: is used to express very large numbers in a simpler way, it’s written in powers of 10

  • M x 10^n

    • m is always between 1-10

    • n is integer aka how many times moving forward/bakward before getting to real number

    • 10 can be replaced w e

  • ex. 2.5 × 10

Measurement: Comparison between unknown and standard quantity

  • be measured in precision and accuracy

    Precision: degree of exactness of measurement (close together)

    • the less uncertainty in measurement the more precise

    Accuracy: describes how well the measurements agrees with real value (middle)

  • Think bow and arrow

PERCENT ERROR FORMULA: (Estimated Number – Actual Number)/ Actual number) x 100

oscillation: movement back and forth at a regular speed

cesium-133: atom used to define the second and its radiation

  • frequency I. 9.192 ×10^9

integer= number w/o decimal

Random conversions you might need to know

1 mile = 1.609 kilometers (km)

1 mile = 1760 foot

3 feet = 1 yard

1 feet = 12 inches

1 in = 2.54 cm

1 meter = 100cm

1 Kelvin = -272.15 Celsius

1 Celsius = 33.8 Fahenheit