Introduction to Physical Science

1. Introduction to Physical Science Chapter 1

2. Science is a process that uses observations and investigations/experiences to gain knowledge about events in nature.

3. Scientific methods An organized set of investigation procedures = scientific method 1. State the problem 2. Research and Gather information 3. Form a hypothesis (Educated guess) – possible explanation 4. Design an Experiment – an experiment tests the effect of one thing on another using controlled conditions • A good experiment includes: a. Control group – the group receiving NO special treatment, stays the same throughout the experiment, standard by which the test results can be compared b. Variable – a quantity that can have more than a single value, value can be changed Dependent variable – value measured at the end of the experiment EX: growth Independent variable – the variable you change to see how it will affect the dependent variable EX: Time c. Only changes one variable d. Constant – factors that do not change in the experiment. 5. Analyze the Data 6. Draw Conclusions 7. Publish Results

5. Theory • If evidence continues to support a hypothesis over and over, the hypothesis can be called a theory. • A theory is an explanation of things or events based on knowledge gained from many observations and investigations.

6. Laws and Technology • Scientific Laws are statements about nature that seems to be true all the time. • Technology is the application of science

7. “Predicting” and “inferring” are closely related, but there is a difference between these two skills. A prediction is a guess about the outcome of an action based on your prior knowledge or factual information in a text. An inference is way to figure out the deeper meaning of a text by “reading between the lines.” Prediction • Process of predicting • To declare or tell in advance • Prophesy; foretell Inference • Process of inferring • To derive by reasoning • Conclude or judge from premises or evidence • Draw conclusions

8. Communicating with Graphs • A graph is a visual display of information or data. Types: 1. Line – Shows the relationship between independent and dependent variable x-axis= (horizontal) independent variable y-axis= (vertical) dependent variable

9. Line Graph

10. Bar Graph 2. Bar – useful to show comparisons or numerical data Ex/ number of students in each class

11. 3. Circle – fixed quantity is broken down into parts Must determine percentages

12. Measurement Standards of Measurements • Accurate measurement are needed to make experiments valid. Accuracy depends upon standards. Standards are exact quantities (amounts) that people agree upon for comparison. The measurement will be represented by a number and a unit. Name Some Units Used to measure each • Liquid • Mass • Length • Temperature • time

13. Measurement Systems 2 types 1. English system of measurement a. Volume (gallon) b. Mass (pound) c. Length (foot) 2. Metric System (International System of Units – SI Units) Base Units • length (meter) • mass (gram) • time (seconds) • Temperature (Kelvin) • Volume (liter)

14. SI Units • The SI Units are used by scientists. The units have prefixes that are used to represent what multiple of ten is being used.

15. SI unit Prefixes Kangaroos hopping down backwards drinking chocolate milk! • Kilo- 1000 • Hecta- 100 • Deca- 10 • Base Unit- 1 • Deci- 1/10 • Centi- 1/100 • Milli- 1/1000 • Multiples of ten are used so that conversions are easily made between each unit.

17. How would you abbreviate these? • Kilogram – ______________ • Hectagram - ______________ • Decagram - ______________ • Gram - ______________ • Decigram - ______________ • Centigram - ______________ • Milligram - ______________

18. How would you abbreviate these? • Kiloliter – ______________ • Hectaliter - ______________ • Decaliter - ______________ • liter - ______________ • Deciliter - ______________ • Centiliter - ______________ • Milliliter - ______________

19. How would you abbreviate these? • Kilometer – ______________ • Hectameter - ______________ • Decameter - ______________ • meter- ______________ • Decimeter - ______________ • Centimeter - ______________ • Millimeter - ______________

20. Conversion Factor Conversion factor is a ratio that is equal to 1. 1000mL = 1 numerator 1L denominator

21. Measuring Distance • Length is the distance between two points. You have to choose a unit to measure in that will be most appropriate.

22. Measuring Volume Volume is the amount of space that is occupied by an object. Volume of a rectangle= Length x Width x Height Unit would be the unit³ Example: cm³ How do you measure the volume of a liquid? You have to measure the capacity of the container. 1 cm³ = 1 mL

23. Measuring MatterMass is the measurement of the quantity of matter in an object. Matter takes up space. Density is the mass per unit volume of a material Density = Mass Volume

24. Measuring Time and Temperature • Time is the interval between two events measured in seconds. • Temperature is measured in Kelvin (K). • Freezing point of Water is 0ºC • Boiling point of water is 100ºC • 0.0K is the coldest possible (known as absolute zero) • Water freezes at 273K and boils at 373K.

25. For the following slides Add Notes to the back of your handout.

26. Scientific Notation*from standard notation to scientific notation • 1. Write # between 1 and 10 • 2. Write (x10) • 3. Count number of spaces the decimal moved and write it as an exponent on the ten • 4. Positive exponent if moved left (making the entire number smaller) • 5. negative exponent if moved right (making the entire number larger)

27. *From Scientific Notation to Standard • 1) For positive exponent move decimal number of spaces to make the number bigger • 2) For negative exponent move decimal number of spaces to make number smaller

28. Scientific Notation PracticeWrite in standard form • 4.543 x 102 • 6.52 x 103 • 6.82 x 10-1 • 7.98 x 10-3

29. Write in scientific notation • 34567 • 2897 • .00987 • .00000734

30. Instruments Used For Measurement

31. Ruler • Used to measure distance or length • Length = the distance from one point to another. Unit = meters • Graduation = one mark on the measuring device. • U S Ruler = 8 graduations • Metric Ruler = 10 graduations

32. Graduated Cylinder • Used to measure the volume of a liquid. • Volume = the amount of space an object takes up. Unit = liters • When measuring water measure from the bottom of the meniscus. From the top of a substance like mercury.

33. Triple Beam Balance • Used to measure the mass of a substance. • Mass = the amount of matter. Unit = grams • Matter = anything with mass & volume. • 3 counter weights are used to indicate the mass. Largest measures the hundreds, middle sized weight measures the tens, and the smallest measures the ones and 1/10 of a gram.

34. Time & Temperature • Time = the elapse time from the beginning to the end of an occurrence. • Unit = seconds. • Temperature = a measure of the motion of the molecules in a substance. • Unit = degrees Celsius, °C.

35. Measurements that Require Calculations • Speed & Velocity • speed = distance ÷ time s = d/t • Unit = meters/second, m/s • Density • density = mass ÷ volume d = m/v • Unit = grams/cubic centimeter, g/cm3 • Area • area = length x width a = l x w • Unit = squared centimeters, cm2 • Volume • volume = length x width x height v = l x w x h • Unit = cubic centimeters, cm3

36. How many seconds are in 3 days? • T = 3 d • 24 hrs = 1 d • 60 min. = 1 hr • 60 s = 1 min. • 3 d = 259,200 s