chapter2_ales

__Chapter 2!__
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Kilograms – Mass Meter – Length Second – Time Mole – Count Kelvin – Temperature Amp – Electric Current Candela – Luminous Intensity
 * Base Units**:

Joule – Energy Newton – Force Pascal – Pressure Volts – Voltage Hertz – Frequency Coulomb – Electric Charge Prefixes added to the names of the SI base units are used to represent quantities that are larger or smaller than the base units.
 * Derived SI Units**:


 * Prefixes:**

T – Tera - 10^12 G – Giga – 10^9 * M – Mega - 10^6 * k – Kilo - 10^3 * h – Hecto – 10^2 D – Deka - 10^1 d – Deci – 10^-1 * C – Centi – 10^-2* m – Milli – 10^-3* μ – Micro – 10^-6* n – Nano – 10^-9 * p - Pico – 10^-12 * f – Femto - 10^-15 a – Atto – 10^-18

Others are there just in case
 * =probably need to know for the final


 * Vocabulary Stuff to know**:
 * Quantity** – something that has magnitude, size, or amount.
 * SI** – Worldwide measurement system consisting of seven base units, additional units are derived from the base units.
 * Volume** – the amount of space occupied by a 3-D object.
 * Density** – how much stuff is in an area
 * Area** - amount of space occupied by a 2-D object
 * Length** – distance from one point to another
 * Width** – how far across an object is
 * Depth** – how deep an object is
 * Height** – how tall an object is
 * Mass** – how much measures the quantity of matter
 * Weight** – measure of gravitational pull on matter

Scientific Method: 1. Observe: watch, measure, and experiment 2. Formulate a Hypothesis: predict and infer 3. Testing: predict, test, talk, collect data, measure 4. Theorizing: make models predict talk and stuff 5. Publish Results: go back to 3 to validate (if necessary).

__Percent Error__- how to determine how accurate your answer is Equation: __What you got minus the right answer__ X 100 The right answer Then absolute value if y (make it positive if necessary) it and put a percent next to it (can and will go over 100%)

Accuracy and Precision

__Accuracy__- the closeness of a set of measurements to the correct or accepted value (a bunch of stuff that’s pretty close to being right)

__Precision__ – closeness of a set of measurements of the same quantity in the same way (a bunch of measurements that are really close __to each other__)

SIG FIGS (significant figures): Significant Figures in a measurement consist of all of the digits known with certainty plus one digit, which is somewhat uncertain or estimated.

Why? Because in measuring stuff you might see it differently than other people.

When not to: definite numbers that cannot be misread.

Rules: 1. Zeros appearing in between non zeros are always significant 2. Zeros before never are significant 3. Zeros at the end of a number and to the right of a decimal point are significant 4. Zeros at the end of a number but to the left of a decimal point may or may not be significant. If a zero has not been measured or estimated but is just a place holder it is not significant. When there is a decimal point at the end then they are significant (eg 3000 =1 sig fig 3000.= 4 sig figs) 5. round to the even if the last number is five otherwise round normally 6. When adding and subtracting decimals, the answer must have the same number of digits to the right of the decimal point as there are in the measurement with the fewest. 7. When multiplying and dividing, the answer can have no more sig figs than are in the measurement with fewest number of sig figs.

Scientific notation: number written like 1.6055 x 104 1. first number must be between 1-10 2. if it has more use a decimal point 3. omit the zeros at the end 4. times it by 10x the number of places it would take it to return to normal

Directly proportional: two numbers are directly proportional if one divides evenly into the other. Represented by y/x=k or y=kx

Inversely Proportional is written like xy=k or y=1/x


 * Practice problems**:

Give amount of SIG FIGs for the following numbers:

1. 300.076 2. 50600 3. 910,000.0 4. 74.0550

Tell whether the following examples are accuracy, precision, both, or neither:

1. A rifle target with 5 tightly packed shots inside the bull’s-eye. 2. A target with 15 shots evenly spread around the circumference. 3. 15 shots widely spread, missing the target.

Find percent error:

1. Carmelo Anthony takes 10 jumps shots, you predict he hits 6, he ends up hitting 9. 2. You predict there are 456 jelly beans in a jar, there are actually 789.

Answer Key: SIG FIGS Questions:
 * 1) 6 SIG FIGS
 * 2) 3 SIG FIGS
 * 3) 7 SIG FIGS
 * 4) 5 SIG FIGS

Accuracy / Precision Questions: 1. Both 2. Accuracy 3. Neither

Percent Error answers:

1. 300 Percent 2. 33,300 Percent