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Chapter 1. Science Skills Page 2. What is science? (3:54). 1.1. Science - system of knowledge & methods used to find it Begins w/ curiosity…ends w/ discovery Curiosity provides ?’s Observing/measuring…means to find answers. Science From Curiosity. Science and Technology.
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Chapter 1 Science Skills Page 2
What is science? (3:54) 1.1 Science - system of knowledge & methods used to find it Begins w/ curiosity…ends w/ discovery Curiosity provides ?’s Observing/measuring…means to find answers Science From Curiosity
Science and Technology Science / technology interdependent Advances in 1 leads to advances in the other Science and Technology (1:39)
Big Ideas of Physical Science Space and Time universe age size Matter and Change Small amt for universe Volume/mass Atoms Protons, neutrons, electrons Forces and Motion Push/pull causes change Laws will explain Energy Many forms Drives motion Transferred/never destroyed
Sec 1.2 Using a Scientific Approachp. 7 Scientific Method - organized plan for gathering, organizing, & communicating info Goal….to solve problem or better understand observed event
A Scientific Method Making Observations Observation – info that you obtain through your senses Inference – conclusions drawn based on observations Develop ? / problem Form Hypothesis proposed answer to ? testable
Testing a hypothesis Manipulated (independent) variable – changed by you to test hyp. Responding (dependent) variable – changes in response to man. var. Controlled variable – factors kept constant to test hyp. Control Group –setup run w/o man.var.
Draw Conclusions – does data support hyp? Develop Theory Scientific Theory – well-tested explanation for observations or experimental results Tells “why” Never “proved” May be revised/replaced Mr. Duey Scientific Method Rap
Scientific Laws Scientific law – summarizes pattern found in nature explains “what” DOES NOT attempt to explain observed pattern in nature
Scientific Models Scientific Models - makes easier to understand things too hard to observe directly Ex. Atomic models, models of the solar system, cell models, etc. The Scientific Method (12:07)
Using Scientific Notation • Written as # btwn 1 & 10 and a power of 10 • Makes very large/small #’s easier to work w/
The Distance From the Sun to the Earth 93,000,000 miles
Step 1 93,000,000 9.3000000 Move decimal left Leave only 1 # in front of decimal
Step 2 93,000,000 = 9.3 • Write the # w/o zeros
Step 3 7 93,000,000 = 9.3 x 10 Standard Form Scientific Notation Count # places decimal moved That’s power of ten
Practice Problem 9.85 x 107 -----> 6.41 x 1010 -----> 2.79 x 10-8 -----> 4.2 x 10-4 -----> Write in scientific notation. Decide the power of ten. • 98,500,000 = 9.85 x 10? • 64,100,000,000 = 6.41 x 10? • 0.0000000279 = 2.79 x 10? • 0.00042 = 4.2 x 10?
Complete Practice Problems Write in scientific notation. 5 x 104 7.2 x 106 8.02 x 1011 • 50,000 • 7,200,000 • 802,000,000,000
Multiplying numbers in scientific notation A rectangular parking lot has a length of 1.1 x 103 meters and width of 2.4 x 103 meters. What is the area of the parking lot? When x #s in sci not, its 2 steps:
Step 1 2.6 1.1 x 2.4 = X base #s
Step 2 6 3 + 3= 1.1 x 103 m x 2.4 x 103 m = 2.6 x 106 m2 add exponents
DID YOU KNOW It’s a metric world The United States is the only western country not presently using the metric system as its primary system of measurement. The only other countries in the world not using metric system as their primary system of measurement are Yemen, Brunei, and a few small islands.
DID YOU KNOW In 1906, there was a major effort to convert to the metric system in the United States, but it was opposed by big business and the attempt failed. The Trade Act of 1988 and other legislation declare the metric system the preferred system of weights and measures of the U.S. trade and commerce, call for the federal government to adopt metric specifications, and mandate the Commerce Department to oversee the program. The conversion is currently under way; however, the metric system has not become the system of choice for most Americans’ daily use.
Lost in space In September 1999, the United States lost the Mars Climate Orbiter as it approached Mars. The loss of the $125 million spacecraft was due to scientists confusing English units and metric units. Two spacecraft teams, one at NASA’s Jet Propulsion Lab (JPL) in Pasadena, CA, and the other at a Lockheed Martin facility in Colorado, where the spacecraft was built, were unknowingly exchanging some vital information in different units. DID YOU KNOW The missing Mars Climate Orbiter
Lost in space The spacecraft team inColoradoused English units of pounds of force to describe small forces needed to adjust the spacecraft’s orbit. The data was shipped via computer, without units, to the JPL, where the navigation team was expecting to receive the data in metric units. The mix-up in units led to the JPL scientists giving the spacecraft’s computer wrong information, which threw the spacecraft off course. This in turn led to the spacecraft entering the Martian Atmosphere, where it burned up. DID YOU KNOW The missing Mars Climate Orbiter
DID YOU ALSO KNOW Lost in space On Jan. 3, 1999, NASA launched the $165 million Mars Polar Lander. All radio contact was lost Dec. 3 as the spacecraft approached the red planet. A NASA team that investigated the loss of the Mars Polar Lander concluded a rocket engine shut off prematurely (due to programming error) during landing, leaving the spacecraft to plummet about 130 feet to certain destruction on the Martian surface.
The Gimli Glider a mix up in units On July 23, 1983 Air Canada Flight 143 (a brand new Boeing 767) ran out of fuel while en route to Edmonton from Montreal at 26,000 feet. Miraculously the caption was able to land the plane on an abandoned Royal Canadian Air Force Base at Gimli, where the runways were converted into two lane dragstrips for auto racing. No one was killed.
The Gimli Glider a mix up in units On July 23, 1983 Air Canada Flight 143 (a brand new Boeing 767) ran out of fuel while en route to Edmonton from Montreal at 26,000 feet. Miraculously the caption was able to land the plane on an abandoned Royal Canadian Air Force Base at Gimli, where the runways were converted into two lane dragstrips for auto racing. No one was killed.
SI Units of Measurement (Metric System) p. 16 LENGTH – straight line btwn 2 pts. meters (m) MASS – amt. of matter in object kilograms (kg) VOLUME – amt. of space occupied by object liters (L)
Common Metric prefixes & values 1000 h deca deci d centi 0.01 (1/100) milli Why scientists use metrics 2:31
Kids (kilo, 1,000) Have (hecto, 100) Dazzling (deca, 10) Uniforms (Unit of measurement) During (deci 1/10) Cross Country (centi 1/100) Meets (milli, 1/1,000)
10 mm = _______ cm 100 kg = ________ g 5296 mL = _____________ L
1 fl oz = 29.573 mL 1- 12oz can of soda = approx 355 mL. 1 gallon = 3.79 liters 1 quart = 0.946 liters It would take approximately 3 ¾ 1-liter bottles to equal a gallon. VOLUME English vs. Metric Units Which is larger? A. 1 liter or 1 gallon B. 1 liter or 1 quart C. 1 milliliter or 1 fluid ounce
kL Metric Units cL mL L Volume is amt of space object occupies Base unit is liter (L). Standard: 1 liter = cubic decimeter Which is larger? A. 1 liter or 1500 milliliters B. 200 milliliters or 1.2 liters C. 12 cm3 or 1.2 milliliters Click the image to watch a short video about volume. Liter Image: http://www.dmturner.org/Teacher/Pictures/liter.gif
What causes the meniscus? A meniscus occurs when molecules of liquid attract molecules of container. Measuring Volume Read the measurement based on the bottom of the meniscus or curve. Read at eye-level with level of liquid. What is the volume of liquid in cylinder? __________ Top Image: http://www.tea.state.tx.us/student.assessment/resources/online/2006/grade8/science/images/20graphicaa.gifBottom Image: http://morrisonlabs.com/meniscus.htm
Measuring Liquid Volume What is the volume of water in each cylinder? Images created at http://www.standards.dfes.gov.uk/primaryframework/downloads/SWF/measuring_cylinder.swf A B C Pay attention to the scales for each cylinder.
8.2 cm 6 cm 9.0 cm We can measure the volume of irregular object using water displacement. Amount of H2O with object = ______About of H2O without object = ______Difference = Volume = ______ http://resources.edb.gov.hk/~s1sci/R_S1Science/sp/en/syllabus/unit14/new/testingmain1.htm Measuring Solid Volume We can measure the volume of regular object using the formula length x width x height. _____ X _____ X _____ = _____ Click here for an online activity about volume. Choose Lessons Volume & Displacement
MASS English vs. Metric Units 1 pound = 453.6 grams 1 oz gold = 28,349.5 mg 100 kg = 220 pounds Which is larger? 1. 1 Pound or 100 Grams 2. 1 Kilogram or 1 Pound 3. 1 Ounce or 1000 Milligrams
Kilogram Prototype A. 1 kilogram or 1500 grams B. 1200 milligrams or 1 gram C. 12 milligrams or 12 kilograms D. 4 kilograms or 4500 grams kg Metric Units cg mg g Mass - amt of matter in object. Base unit is kilogram (kg) Standard: 1 kg = mass of International Prototype Kilogram (IPK), a platinum-iridium cylinder kept by the Bureau International des Poids et Mesures (International Bureau of Weights and Measures [BIPM]) . Click the image to watch a short video about mass. Which is larger? Kilogram Prototype Image - http://en.wikipedia.org/wiki/Kilogram
Once you have balanced the scale, you add up the amounts on each beam to find the total mass. What would be the mass of the object measured in the picture? _______ + ______ + _______ = ________ g Measuring Mass Objects placed on pan Starting with largest weight, move weights on beams until lines match up. Top Image: http://www.southwestscales.com/Ohaus_Triple_Beam_750-SO.jpgBottom Image: http://www.regentsprep.org/Regents/biology/units/laboratory/graphics/triplebeambalance.jpg
1st – Place the object to be massed on the pan. 2nd – Slide the large weight to the right until the arm drops below the line. Move the rider back one groove. Make sure it “locks” into place. 3rd – Repeat this process with the top weight. When the arm moves below the line, back it up one groove. 4th – Slide the small weight on the front beam until the lines match up. Measuring Mass – Triple-Beam Balance 5th – Add the amounts on each beam to find the total mass to the nearest tenth (0.1) of a gram. Estimate your final digit to the nearest hundredth (0.01) of a gram Click here to try an online activity.
Limits of Measurement Precision gauges how exact a measurement is NFL flyovers 4:53 How precise are the clocks on the right? Top analog clock is precise to the minute Digital clock is precise to the second
Accuracyis closeness of a measurement to actual value • This clock is running 15 minutes slow…… • precise to nearest second BUT • time not accurate
Significant figures (digits) • “Sig Figs” - all digits of known measurement + 1 estimated digit • Answer can only be as precise as least precise measurement in calculation • more precise, more sig figs