Physical Science: CH 2 , Sec 1 Page 40

Warm Up Make a list of observations about the picture Form a scientific question about the picture. Make a hypothesis. Describe data and tools you would need to test your hypothesis.

Data in Science The Big Idea: Scientists use tools to collect, organize, and analyze data while conducting investigations. Tools must be accurate.

International System of Units (AKA Metric System) Universal system for science System works by multiples of 10

Metric System Conversions Brain Pop King Henry Doesn’t Usually Drink Chocolate Milk Kilo, Hecto, Decka, Unit, Deci, Centi, Mili Put your pencil on the unit you are starting with Loop from letter to letter until you reach the unit you want. Count the loops Move the decimal that many times in the same direction you move the pencil

Units Length is in meters (m) Mass is in grams (g) Volume is in liters (L) or meters3 (m3) 1mL = 1cm3 Density is measured by Mass / Volume grams/ liters or meters3 ( 1 g/cm3 or 1 g/L)

Temperature Temperature is in Kelvin (K) or degrees Celsius (°C), (Not Fahrenheit) 0°Celsius = 273 Kelvin To convert Celsius to Kelvin just add 273 100°C + 273 = 373 K

Practice What is the density of an object with a mass of 15g and volume of 3 cm3? Normal body temperature is 37°C, what is that in Kelvin? 26 cm = ____ hm 91 m = ____ km 6 km = ____ mm

Practice Answers 15g ÷ 3cm3 = 5 g/cm3 37°C + 273 = 310 K 26 cm = 0.0026 hm 91 m = 0.091 km 6 km = 6,000,000 mm

Homework TO BE COMPLETED IN NOTEBOOK Define Vocabulary words on page 42: Mass, volume, density, temperature, model, theory, and law. Section Review page 49: Questions: 1, 3, 4, 5, 12

Models in Science Models are representations of an object or system.

Physical Models Show an example at a reasonable scale. Examples: model airplanes, model solar system, model of an atom.

Conceptual Model Explains or summarizes with words Big Bang Model: 12 to 15 billion years ago an event called the big bang sent matter in all directions. This matter eventually formed the galaxies and planets.

Mathematical Models Uses math to represent the physical world. Simple math models: Force = Mass x Acceleration E=Mc2 Complex math models: Quantum Mechanics wave function of a particle:

Limits of Models A model is not exactly the same as the real thing it represents Example: There are many limitations of this model of the solar system: Can you find some?

Scientific Theories Theory is an explanation for many hypotheses and observations.  theory of evolution, the theory of relativity, the atomic theory, and the quantum theory Theories can be changed.

Scientific Laws A summary of many experimental results and observations. Only tells you what happens, (not why or how) The law of gravity, Newton's laws of motion, Conservation of mass

Homework 9/21/10 TO BE COMPLETED IN NOTEBOOK Due 9/22/10 Section Review page 49: #s 2, 6 -11, and 13