HW- Calculation with Scientific Notation Multiply (7.9 x1012) X (6.1x108) (3.4x102)X(4.1x10-4) (3.0x10-2)X(2.1x10-1) (1.2x1015)X(6.9x1011)   Divide (6.3x102)X(2.9x104) (7.9x10-3)X(1.2x10-2) (8.2x105)X(4.1x105) (9.3x1011)X(3.1x103)

Standard Unit Of Measurements The metric system is based on a base unit that corresponds to a certain kind of measurement Length = meter Volume = liter Weight (Mass) = gram Prefixes plus base units make up the metric system Example: Centi + meter = Centimeter Kilo + liter = Kiloliter

Standard Unit Of Measurements SI base units The SI is founded on seven SI base units for seven base quantities assumed to be mutually independent, as given Length = meter - m Weight (Mass) = Kilogram - kg Time= second – s Temperature = Kelvin - K Amount (number of particles) = Mole – mol electric current= ampere - A luminous intensity = candela – cd

SI derived units Other quantities, called derived quantities, are defined in terms of the seven base quantities via a system of quantity equations. The SI derived units for these derived quantities are obtained from these equations and the seven SI base units. Examples of such SI derived units are given

SI derived units area = square meter - m2 volume = cubic meter - m3 speed, velocity = meter per second - m/s acceleration = meter per second squared -  m/s2 mass density = kilogram per cubic meter - kg/m3 specific volume = cubic meter per kilogram - m3/kg Take the base and derived units and construct simple equations that you could use to calculate these measurements. http://physics.nist.gov/cuu/Units/units.html

Significant Figures Significant figures are critical when reporting scientific data because they give the reader an idea of how well you could actually measure/report your data. Before looking at a few examples, let's summarize the rules for significant figures. 1) ALL non-zero numbers (1,2,3,4,5,6,7,8,9) are ALWAYS significant. 2) ALL zeroes between non-zero numbers are ALWAYS significant. 3) ALL zeroes which are SIMULTANEOUSLY to the right of the decimal point AND at the end of the number are ALWAYS significant. 4) ALL zeroes which are to the left of a written decimal point and are in a number >= 10 are ALWAYS significant. A helpful way to check rules 3 and 4 is to write the number in scientific notation. If you can/must get rid of the zeroes, then they are NOT significant.

Complete the following table Number # Significant Figures Rule(s) 48,923 5 1 3.967 900.06 1,2,4 0.0004 (= 4 E-4) 8.1000 501.040 1,2,3,4 3,000,000 (= 3 E+6)