Chapter 1: Science Foundations of Science

1. What is Science? Science = A system of knowledge based on facts or principles –Observation = gathered data that can be seen, heard, tasted, smelled, or touched –Inference = a logical interpretation based on prior knowledge or experience

Branches –Social sciences –Natural science (Biology, Physical science, Earth science)

2. Scientific theories and laws Science is an ongoing process; information improves and changes Theory = a tested, possible explanation of a natural event –Simple and clear explanation –Experiments must be repeatable –Theory can be used to predict things

Law = a summary of an observed natural event

3. The Scientific method Sci. Method = A series of logical steps to follow in order to solve problems –Observe –Formulate a question –Collect data –Form a hypothesis = Proposed explanation of observed events –Conduct experiment –Collect data –Draw conclusions

Control = Condition in experiment that is kept the same Variable = Anything that can change in an experiment

Metric System 1. What is it? A system of measure based on water that converts in increments of 10s. 10 these = 1 those 10 those = 1 that 10 that = 1 them Advantage: easily converted and used across the world What are some of the things that we measure? –HeightVolume –LengthWeight

2. Metric Math Prefixes Each prefix indicates ten times more than the previous With each conversion of unit (change in prefix) you will multiply by 10 or divide by 10 – Moving right x 10 –Moving left ÷ 10 KingHenryDiedBy drinking chocolate milk KiloHectoDecaBasedecicentimilli

each time I multiply by 10 watch what happens to the decimal –1 x 10 = 10. –20 x 10 = 200. –300 x 10 = the opposite happens when I divide by 10 –3000 ÷ 10 = 300 –200 ÷ 10 = 20 –10 ÷ 10 = 1 The decimal slides one place with each x or ÷ by 10, so use the simple sliding method

Steps of Metric conversion –1. draw your metric line: KHDbdcm –2. figure out which direction you will be moving –3. determine how many times the decimal has to slide between the units –4. move the decimal in the given number –5. Check to make sure the answer makes sense

Example 1: 6 Km = _________________m –1. KHDbdcm –2. K.HDb.dcm (starting at kilometer and ending at meter)… moving right –3. decimal moves three spots –4. 6 Km = 6000 m –5. Yes, there are more meters in a kilometer

Practice: –526 m = cm –8000 cm = 0.08 Km –0.40 m = 400 mm – Km = 0.3 m

3. Scientific Notation Does anyone know what a googol is? –1 followed by 100 zeros –Would you write it out? Scientific notation = a method of writing or displaying large numbers in a simple format by sliding the decimal and accounting for the slides by multiplying by ten

Number (1 to 9.9) x 10 exponent 234 becomes 2.34 each slide of decimal = x 10 = exponent A googol is 1 x

Practice: –2500 = 2.5 x 10 3 – = x 10 6 – = 2 x – = x 10 -4

Accuracy vs. Precision The dictionary definitions of these two words do not clearly make the distinction as it is used in the science of measurement.

1. Accurate : "capable of providing a correct reading or measurement." In physical science it means 'correct'. A measurement is accurate if it correctly reflects the size of the thing being measured.

2.Precise means "exact, as in performance, execution, or amount. " In physical science it means "repeatable, reliable, getting the same measurement each time."

We can never make a perfect measurement. The best we can do is to come as close as possible within the limitations of the measuring instruments.

For example a metric ruler which has millimeter marks has a least count of 1 mm or 0.1 cm. and when properly used it can make more precise measurements than one with centimeter marks.

It is "six point something": more than six but less than seven. With certainty we can say it is in the range of 6 to 7. Exactly where in that range is an estimate. We might guess it is 40% of the way, just less than halfway, between 6 and 7 or 6.4.

It is clear that our estimate was close, but the measurement still does not align with a mark. Not only that, but we are having trouble reading the marks now because they are so fine. Now we can estimate with a higher precision that the measurement is 6.39, although you might say that it is 6.38 or even Whatever it is, your best guess is 'correct' although it is not certain.

Density Density is a physical property of matter - the mass per unit volume of a substance - how much “stuff” is in a certain “space” - density remains the same for any volume of a pure substance

If something is known as being “light”… it probably has a small density Common densities SubstanceDensity g/cm 3 Water (l)1.00 Water (s) – ice0.92 Lead11.3 Air (mixture)

Density Math – density is calculated by dividing the object’s mass by its volume. - density = mass = g = g volume cm 3 ml

Example 1: If a box has a volume of 3.0 cm 3 and a mass of 9.0 g, what is its density?

Example 2: If a liquid has a volume of 200 cm 3 and a mass of 800 g, what is its density?

Gasoline has a density of 0.7 g/mL. If your 4-wheeler uses 1,000 mL of gas doing donuts in the lawn, how much lighter is your ride (what mass of gas was used)?