1. What Is Physics?? The science of matter and energy and their interactions Involves: Motion, Fluids, Heat, Sound, Light, Electricity & Magnetism, Simple Harmonic Motion, along with modern topics of: Relativity, Atomic Structure, Nuclear Physics, Elementary Particles, and Astrophysics.

2. Uncertainty Every measurement has uncertainty, not just from blunders, but from accuracy of measurement. To help account for uncertainty we use significant figures.

3. Significant Figures The number of reliably know digits. If you use more than the reliably known number of digits, then you will add to the uncertainty of your answer.

4. How many Sig Figs??? 44.50 4.091 2 100 3

5. How many Sig Figs??? About 100 1 99.009 5 550.00 5

6. Measuring with Sig Figs In measuring sig figs depend on the measuring instrument. Always guess the last decimal, and the last guessed decimal is considered to be significant. Meter sticks, Triple Beam Balances, Stopwatches

7. Calculations with Sig Figs in Multiplication and Division The answer will have the same number of sig figs as the number that has the LEAST number of sig figs in the problem. 34.5 x.009 =.3141 =.3

8. Calculations with Sig Figs in Addition & Subtraction Can go to the first column from the right that both numbers have sig figs

9. Dealing with Formulas Always treat numbers in formulas as an infinite number of sig figs. The 2 in this formula will not give you an answer with 1 sig fig.

10. Units, Standards, and the SI System Standards Length = Meter (m) Used to be 1/10,000,000 of the distance from the equator to either pole Now 1,650,763.73 wavelengths of a orange light emitted by Krypton 86. Time = Second (s) 1/86,400 th of a mean solar day.

11. SI Units Base Quantities Length = Meter (m) Time = Second (s) Mass = Kilogram (kg) Current = Ampere (A) Temperature = Kelvin (K) Amount of Substance = Mole (mol) Luminous Intensity = Candela (cd)

12. Derived Quantities These are all other units in the SI system of units. These are all derived from the base quantities. For instance a force is a This is the combination of distance, mass, and time to make up the unit for force.

13. Metric Prefixes PrefixAbbreviationValue TeraT10 12 GigaG10 9 MegaM10 6 Kilok10 3 Hectoh10 2 Dekada10 1 Decid10 -1 Centic10 -2 Millim10 -3 Microm10 -6 Nanon10 -9 Picop10 -12

14. Examples Convert $325,000,000 to M$ Convert 1.2 km to mm. Convert 120,000 ng to cg. Convert 93,000,000 mi to m Convert 55 mi/hr to m/s. Convert 2.34 x 10 9 in to km