let’s investigate great white shark ‘jaws’ an object that is streamlined will move faster...
TRANSCRIPT
Let’s InvestigateLet’s Investigate
Great white shark ‘Jaws’
An object that is streamlined will move faster
through water than an object that is not streamlined
http://www.webweaver.nu/clipart © Sheila Porter – www.scifest.ie
Testing a HypothesisTesting a HypothesisHypothesis: An object that is streamlined will move faster through
water than an object that is not streamlined.
Materials: Blu-Tack, tall measuring cylinder & stopwatch
1. Discuss the hypothesis with the other members of your team.
2. Identify the variables (see slides 6 and 7).
3. Draw up an experimental plan.
4. Design a chart on which to record the data you collect.
5. Carry out investigation (Remember you may have to modify your
original plan.)
6. Write an account of the investigation into your copybook,
explaining your method and describing your results and
conclusions.
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Independent VariableIndependent Variable
Dependent VariableDependent Variable
Fixed Variables/Fixed Variables/
ConstantsConstants
Replicates - Number of Replicates - Number of times each shape was times each shape was testedtested
© Sheila Porter – www.scifest.ie
Complete the ChartComplete the Chart
Complete the ChartComplete the Chart
Independent VariableIndependent Variable
Dependent VariableDependent Variable
Fixed Variables/Fixed Variables/
ConstantsConstants
Replicates - Number of Replicates - Number of times each shape was times each shape was testedtested
Shape
Time taken to travel distance/speed
1. Mass of object 2. Distance/Height of water 3. Height of drop
ThreeThree
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Sample Table of ResultsSample Table of ResultsShapeShape Trial 1Trial 1
Time Time (s)(s)
Trial 2Trial 2
Time Time (s)(s)
Trial 3Trial 3
Time Time (s)(s)
AverageAverage
Time (s)Time (s)DistanceDistance
cmcmSpeedSpeed
cm/scm/s
112233
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DiscussionDiscussion
What problems did you come across in your experiment ?What problems did you come across in your experiment ?
How did you overcome these problems ?How did you overcome these problems ?
The scientific method is limited in a number of ways, e.g. by the extent of our basic knowledge and changes in the natural world. Can you think of any other factors that might affect the validity of your results.
In all practical work safety must be a major concern. Give examples of two safety precautions you observed when carrying out this investigation.
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Animals that move through waterAnimals that move through water
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Extended DiscussionExtended Discussion
1. 1. Some fish have fusiform (streamlined) bodies, e.g., Some fish have fusiform (streamlined) bodies, e.g.,
salmon while others are laterally compressed salmon while others are laterally compressed
(flattened from side to side), e.g., sole. The shape of (flattened from side to side), e.g., sole. The shape of
the fish’s body tells us a lot about its lifestyle. the fish’s body tells us a lot about its lifestyle.
Comment on this statement.Comment on this statement.
2. 2. In what way might the results be useful if you were In what way might the results be useful if you were
designing swimwear?designing swimwear?
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