sci methods ch1.2 8th

8/14/2019 Sci Methods CH1.2 8th

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Chapter 1 Section 2


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Students will be able to: Explain what scientific methods are.

Explain how scientific methods are used to answer

questions

Describe how a hypothesis is formed and tested

Identify methods that are used to analyze data

Explain how a conclusion can support or disprove ahypothesis

List methods of communicating data


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Series of steps followed to solve problems

Do you know what the steps are?

Take a minute to write down the steps asyou know them


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Ask a question

Form a hypothesis

Test the hypothesis

Analyze the results

Draw conclusions

Communicate results


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Focuses the purpose of an investigation

Make observations Gather information through your senses

Accurately make and record your observations


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How can you improve the efficiency of boatpropulsion systems?

Experimenters: Czarnowski (zhar NOW skee)

andTriantafyllou (tree ahn ti FEE loo)


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Most boat propellers are only 70% efficient

Increased efficiency will save resources

(fuel) and money


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Hypothesis: a possible explanation oranswer to a question

Based on your observations

Can be tested

Predictions : statement of cause and effectthat can be used to set up a test for ahypothesis (if-then format)


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Penguins swimming in the New EnglandAquarium


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Controlled experiments: tests only onefactor at a time; a control group and 1 ormore experimental groups.

Only one factor differs, this is the variable

Designing an experiment

Collecting data


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Czarnowski and Triantafyllou built Proteus,a 2-propeller penguin boat

They tested it in the Charles River in Boston

They collected and recorded data such asthe flapping rate, energy used by the

motors, and the speed achieved by theboat.

The only factor that was changed was theflapping rate


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Organize your data (tables, graphs, etc.)

Helps to explain and focus on effects of thevariable


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By graphing data on flaps per second,Proteus was most efficient at 1.7 flaps persecond

Graphing efficiency showed that Proteus is17% more efficient than a propeller-drivenboat.


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Do the results of the experiment supportthe hypothesis?

If not, need to find another explanation

Problems are rarely solved with just oneexperiment


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After many more trials, Czarnowski andTriantafyllou found that the penguinpropulsion system was more efficient thanthe propeller propulsion system.

This led to more questionsCan this systembe used on large tanker ships?


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Share with others to learn more and expandyour ideas

Compare hypotheses

Repeat experiments

Develop new experiments and hypotheses


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Published their results in academic papers,science magazines, and newspapers

They also displayed their results on theInternet

This way, other scientists can conduct

additional research about Proteus


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What is the relationship between andexperiment and a hypothesis?

When following scientific methods, what isthe correct procedure for investigation?

sci methods ch1.2 8th

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