Metric Conversions/Scientific Notation/ Dimensional Analysis Adv Physics Chapter 1 Review

Measuring Systems Two major systems of units in use today - metric system - British system (only used by US)

International System of Units Abbreviated SI Modern version of the metric system Designates base units

Length Meter (m) Originally defined as 1/10000000 of the distance from the North Pole to the equator along a meridian running through Paris Today 1 m is the distance traveled by light in a vacuum in 1/299792458 seconds

Mass Kilogram (kg) Referenced to a standard kept at the International Bureau of Weights and Measures in France

Time Second (s) Defined by the radiation frequency of the cesium – 133 atom 1 second = 9192631770 oscillations

Metric System Major advantage is that it is based on powers of 10 Most common prefixes are kilo-, centi-, and milli-

Dimensional Analysis Method of using equivalence statements to convert from one unit to another Example – Convert 12 feet into yards. 12 ft x (yd / 3 ft) = 4 yd

Dimensional Analysis This is the Method I want you to use: Place the unit you want as your answer on top. Place the unit you want to cancel on the bottom. Always go to the base 1st!!!! Notes: Always place the power of 10 with the base unit (example: 10^3 m) --- base units will be m, g, s, etc. Does the answer make sense? STAIR STEP If between k(kilo) and m(milli) you can use stair step method… (ex: 20km to 1 dm) kentucky has dark black deep coal mines 10^3 10^2 10^1 base 10^-1 10^-2 10^-3 20.0 Answer

Dimensional Analysis Convert 20 km to m. Convert 100g to dg .

Dimensional Analysis Convert 5 μm to m. Convert 500 kg to Mg . Convert 4500 ps to ns. The area of an object is 137 km2. Express this area in m2.

Scientific Notation Easier method of writing really small or really large numbers Ex – 3,400,000 is the same as 3.4 x 106 Ex – 0.00047 is the same as 4.7 x 10-4 What does it mean to say that motion is relative? - how you describe an object’s change in position is determined by where you choose to measure it from -ex – you are rest relative to desk, in motion relative to sun

Scientific Notation Express 53,200,000 in scientific notation. What does it mean to say that motion is relative? - how you describe an object’s change in position is determined by where you choose to measure it from -ex – you are rest relative to desk, in motion relative to sun

Dimensional Analysis #2 Convert 12 years to minutes. Convert 23 miles to km (1 mile = 5280 ft, 3.28 ft = 1 m). Convert 5 mph to m/s. How many seconds would it take to run a mile(1.6 km) at the 5 mph? (how many minutes is this?)