Projectiles

1
Projectiles
Science 10 ACSC MOTION UNIT Data Recording Skills

• On Target
• with
• ACCURACY and Reliability

2
OVERVIEW Data Recording Skills

• A- Recording Measured Numbers
• B- PROJECTILE LAUNCHER
• VEGGIE GUN SHOOTING RANGE
• C- Reading Measured Numbers
• ACSC Skill Outcomes
• Introduction to recording analyzing and
  interpreting Data
• 214-5, 214-8, 214-10, 215-2

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Measured NumbersSignificant Figures Features
Benefits skip to end -gt

• Features, Significant Figures include the
  following
• All accurately known digits are recorded
• One digit with opinion is recorded, (estimate
  tenths in the smallest graduation)
• Counted and defined numbers have infinite
  significance.
• Benefits
• Accurately recorded digits give clues to the
  reliability and reproducibility of the data.

4
Preparing the Projectile Range

• Stakes were driven in every 10m
• Range measurement includes the following
• All accurately known digits and
• One estimated digit and the uncertainty 1m, in
  this case.

5
Measuring the Projectile Airtime

• First measure the stopwatch-finger reaction time
  by turning the watch on and off as quickly as
  possible.
• Shoot the projectile straight into the air 4-6
  times and measure airtime with the same
  stopwatch.
• record a minimum and maximum airtime with
  reaction uncertainty

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Prediction Corridor of Success

• The experimental max./min. airtimes were added to
  the spreadsheet.
• Then the graph will update to show the expected
  minimum and maximum range of the projectile.

• Is there more than one approach to a target for
  a projectile? Explain

7
Data Collection How much data is enough?
Skip to end-gt

• Test (Practice) until the trials are fair tests.
  (trials must be comparable and consistent)
• Test ( Bias) practice the method until method
  biases or the lack of them become obvious.
• Test (Trends) collect data until trends or lack
  of them become obvious)

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Data Graphing How well does the real data fit?
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• Plot the test data on the graph to see how well
  the actual trials fit in the corridor of success
  as predicted from the minimum and maximum
  airtime.
• Compare launch angles,Are all ranges equally
  reliable?
• If you had to hit a target accurately are some
  angles better to shoot from? How is this
  indicated by the corridor of success?
• In this case is more reliable likely to be more
  accurate?

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Data Graphing How well does the real data fit?
Back-gt
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Controlling Variables

• There are several practical things which can be
  done to control variables.
• Do all trials, to be compared, on the same day.
• Use projectiles of the same mass.
• Practice firing until you can collect reliable
  data and the tests are fair.
• Use the same can of spray, gun and firing team to
  collect the data.

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Internet Availability

• Science 10 ACSC development site
  http//scifair.ednet.ns.ca/science10
• Nova Scotia Teachers Professional Development
  Resource http//nstacme.acadiau.ca
• Central Kings Science 10 http//scifair.ednet.ns.c
  a/CKCLS/indexPHS.html
• Review Buttons
• Recording Significant figures
• Data Collection (How much is enough?)
• Controlling Variables