Chapter 1 Lesson 2 “The Scientific Method” Key Concepts… What is the scientific method? What is the SI System? Why should we learn the SI System?

I. What is the Scientific Method? (Ex. Pg. 13) A. An organized plan used to help solve a problem. B. The General Idea… -Use your senses. “The lights went out in my room…” -What do you want to know? “What caused the lights to go out?” -Find out any information. “Check to see if other lights work.” -Make an educated guess using what you already know. “The lights went out because ___________.” Observations Ask a Question Research Form a Hypothesis

-Run a controlled experiment. Keep all variables the same and change only one. Turn on other lights, blown fuse, broken bulb… -Look at the data and facts. No other lights work; it is storming outside Conclusion: Lightning/wind broke a power line *If no good answers are available go back and find more research and start the process over again. Test / Experiment Draw Conclusion

II. Using Scientific Notation A. A way of expressing a number as a value and a power of Why use it??? -easy to use large/small numbers a. 400,000,000  b. 35,300  c  d x  4.0 x x x

Activity (5-7 min) 1. Use a pen/pencil and measure the length of the table you are sitting at. 2. Record your measurement 3. Repeat using a different pen/pencil 4. Record your measurement Think…Why are your measurements different from each other???

III. Standards of Measurements A. Standard – an exact quantity that people agree on. 1. Ex: a = 12 inches 2. a mile = 5280 feet

IV. Different Systems A. English System – feet, gallons, cups, inches… 1. U.S. only country to use it. B. SI System by the French 2. Used worldwide 3. Based on powers of 10

Common Prefixes (pg. 17) Giga  ,000,000,000 Mega  ,000,000 Kilo  ,000 Hecto  Deka  Base  Deci  Centi  Milli  Micro  Nano 

Examples 1. Convert 1.0 m to dm?  10 decimeters 2. A road is 1000 m in length. What is this in km?  1 kilometer 3. A small new planet is found 3 light years away from Earth. If the diameter of this planet is 23,500 meters, how many kilometers is its diameter?  23.5 kilometers

Assignment millimeters  centimeters kilometers  meters micrometer  millimeters Megameters  kilometers hectometers  millimeters 6. 1,234,567 micrometers  Megameters x 10 3 deciliters  liters

Answers to previous: cm m mm km mm Mm L

SI System Introduction mg Prefix Unit measured milli gram

Length A. Def – the distance between 2 points 1. base unit = meter 2. Ex: meter, millimeter, hectometer

Volume (derived unit) A. Def. – the amount of space occupied 1. formula: length X width X height a. Must be same units 2. base unit = liter (liquids); meter (solids) a. **1 cm 3 = 1 ml** 3. solids are always cubed (cm 3, m 3 ) 4. is a derived unit

Volume Example A liquid is poured into a container. If the dimensions of the container are 45 cm, 54 cm, and 80 cm what is the volume of the liquid in cm 3 ?  194,400 cm 3 The sides of a box are 45 cm, 54 cm, and 0.4 dm. What is the volume of the box in cm 3 ?  9,720 cm 3

Mass A. Def. – the amount of matter in an object 1. base unit = gram 2. kilograms is used frequently

Density (derived unit) A. Def. – Mass per unit of volume 1. formula: density = mass / volume 2. is a derived unit

Density Example What is the density of an unknown metal that has a mass of grams and a volume of 20.0 mL? ***Remember D=M/V***  8.9 grams/mL Will this object float in water??? (1.0 g/ml) NO

Time and Temperature A. Def. – Time is the interval between two events. 1. Base unit = second B. Def. – Temperature is the amount of heat contained in a substance 1. Base unit = Kelvin/Celsius

Temperature Scales a. Celsius Scale – used for most scientific work i. 0 = freezing point of water ii. 100 = boiling point of water iii. 20 = room temperature iv. 37 = body temperature b. Kelvin scale i. 0 on the Kelvin Scale is absolute zero (-273 C.) ii. to convert Celsius to Kelvin add 273 K iii. to convert Kelvin to Celsius subtract 273 K

Temperature Example The outside temperature is 29 degrees Celsius. What is it in Kelvin?  302 Kelvin A person has a temperature of 313 Kelvin. Does this person have a fever?  yes; the body temp is 40 deg C.