1/6/11
Post date: Jan 05, 2011 9:25:33 PM
Bell ringer: What is scientific notation and when is it useful?
Purchase lab manuals ($1.25)
Turn in lab safety contracts, syllabus agreements
Quiz tomorrow:
1. Scientific knowledge / ideas
2. Putting numbers into and out of scientific notation
3. Arithmetic with scientific notation.
Measurement notes
Measurements ...
Are a form of observation
May provide evidence to help us formulate a theory
Accurate measurements help us make more accurate theories
Are based in time, distance, and mass
The SI system (the metric system)
Used everywhere except USA and Australia (and sort of Britain)
Used in SCIENCE
Uses prefixes to make larger or smaller increments
Time (second) - related to frequency of radiation from Cs-133
Distance (meter) - distance traveled by light in a vaccuum in 1/ (299,792,458) seconds
Mass (kilogram) - mass of a platinum-iridium rod kept near Paris
Distances
How far between two points
Basic unit is the meter (m)
For small measurements, we use the centimeter (1/100th of a meter) or the millimeter (1/1000th of a meter)
For large measurements, we use the kilometer (1000 meters)
To measure distance, we can use meter sticks and rulers
Work time for measurement lab (due Friday)
Scientific notation notes
Used to express very large or very small numbers
General format is M x 10^n
M is the non-zero numbers at the left side of a very large or small number. M is always a number with only one digit to the left of the decimal
n tells us how far to move the decimal place (positive means right, negative means left)
e.g. 4.5 x 10^3 is the same as 4500 (decimal in 4.5 was moved to the right 3 places)
e.g. 6.8 x 10^-3 is the same as 0.0068 (decimal in 6.8 was moved to the left 3 places)
Read "Scientific Notation" on pages 15-16
Do Page 16: 1-3, 6-7, 9-10 for practice
Practice problem recommendations:
Write problem, work, and answer
Check answer only AFTER completing the problem
Cross out, don't erase
Write yourself tips as you work
Ask yourself, "what am I likely to forget between now and the test and/or final exam?"