Chapter 1 Science & Technology

Science: (and technology)  has help societies throughout history to advance and even helped many thrive above other cultures. It is an organized way of investigating the natural world and put resources to a beneficial use.

3 Examples  Weapons = to protect the people, gain new land & resources  Agriculture = to feed the people which help prevent civil unrest  Medicine = to cure and prevent diseases so the people may live longer

Terms  Scientific Law: Statement of fact backed up by proven research.  Theories: Ideas or beliefs supported by data, but NOT proven.

Scientific Method: a logical method to solve ANY problem.

Scientific Method  State the Problem = needs to be well defined  Gather information = (Research the Problem) become an expert on the problem  Form the Hypothesis = through research; an educated guess at a solution to the problem  Test = run a controlled experiment to test the hypothesis by Recording & analyzing data  State Your Conclusion = evaluate the success of the hypothesis. Adjust and Retest as necessary

Testing the Hypothesis  Trials = number of times the experiment was ran. Needs to be a high number to add credibility to the work  Variables = conditions (or factors) that changed during the experiment & factors being tested  Independent variables answer the question "What do I change?"  Dependent variables answer the question "What do I observe?" *On a Graph = dependent variable goes on the y- axis, independent variable on the x-axis *On a Graph = dependent variable goes on the y- axis, independent variable on the x-axis

Specimen Groups  Control Group = a group that had NO changes in their conditions. Conditions that stay the same throughout the tests. Used to set what is NORMAL from which comparisons are made  Experimental Group = a group(s) that have the independent variable introduced

90 mice are ran through a maze to get the average for that maze. 30 mice Control Group NO MUSIC 30 mice Experimental Group ROCK MUSIC 30 mice Experimental Group CLASSICAL MUSIC 5 minutes was the average (all 90 mice) 2 Weeks 24 hours per day music played in living areas Mice, Music and a Maze

Questions  Name the variables.  What time MUST the control group have in order to declare any results as valid?  Why must all 3 groups get the exact same amount of food & water?  What is the purpose of the maze?  What are your predictions?

Actual Results

What is your conclusion?

Instruments = tools used to record and analyze data from an experiment.  Length = Ruler … measured in meters, centimeters, kilometers, etc.  Mass = Balance … measured in grams  Temperature = Thermometer … measured in degrees Celsius (°C)  Area = Ruler … Area = L x W  Volume –Ruler = regular shaped objects Volume = L x W x H –Graduated Cylinder = liquids …measured in milliliter, cubic centimeters, liters, etc. –Water Displacement = irregular shaped objects  Density = Balance & Ruler… Density = mass ÷ volume (D = m/v)

Metric System = units of measurement based on the power of 10 by the use of prefixes  Kilo (k) – 1000x  Hecto (h) – 100x  Deca (da)– 10x  Base Unit  meter (m), liter (l) or gram (g)  Deci (d) – 1/10x  Centi (c) – 1/100x  Milli (m) – 1/1000x

King Henry Died Drinking Chocolate Milk kilo- hecto- deca- BASE deci- centi- milli- Example: base unit is meter. kilometer, hectometer, decameter, meter, decimeter, centimeter, millimeter

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

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.

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.

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.

Measurements that Require Calculations  Speed & Velocity speed = distance ÷ times = d/tspeed = distance ÷ times = d/t Unit = meters/second, m/s Unit = meters/second, m/s  Density density = mass ÷ volumed = m/vdensity = mass ÷ volumed = m/v Unit = grams/cubic centimeter, g/cm 3 Unit = grams/cubic centimeter, g/cm 3  Area area = length x widtha = l x warea = length x widtha = l x w Unit = squared centimeters, cm 2 Unit = squared centimeters, cm 2  Volume volume = length x width x height v = l x w x hvolume = length x width x height v = l x w x h Unit = cubic centimeters, cm 3 Unit = cubic centimeters, cm 3

A race car travels at a constant speed. Position and time data are recorded. A graph is prepared using the data. Use this graph to determine the speed of the race car.   d = 60 m   t = 0.8 s   s = ?   speed = distance ÷ time ( s = d/t)   speed = 60 m ÷ 0.8 s   speed = 75 m/s

Name the seven basic metric units for length longest to shortest.  Kilometer  Hectometer  Decameter  Meter  Decimeter  Centimeter  Millimeter

How many seconds are in three (3) days? 3 days 24 hrs 60 min 60 sec 1 day 1 hour 1 min 1 day 1 hour 1 min 3 days 24 hrs 60 min 60 sec 1 day 1 hour 1 min 1 day 1 hour 1 min 3 x 24 x 60 x 60 = 259,200 = 259,200 sec 1 x 1 x 1 = 1

An automobile travels at 30 m/s for 2 minutes. How far did it travel?  d = ?  t = 2 min. (must be converted to seconds) = 120 s  s = 30 m/s  d = s x t  d = 30 m/s x 120 s  d = 3600 m

In one-half hour, a bicyclist traveled 20 km. What was the bicyclist’s average speed?  d = 20 km  t = 0.5 hr  s = ?  s = d ÷ t  s = 20 km ÷ 0.5 hr  s = 40 km/hr

Some Basic Science Knowledge  Water = Melting Point (or freezing point) is 0°C  Water = Boiling Point is 100°C  Normal Body Temperature = 37°C  Comfortable Room Temperature = 22°C  “Standard” Room Temperature = 20°C  Density of water = 1.0 grams per cubic centimeter