2/15 Warm-up – answer in short sentences

• Which ball lost the most energy with each bounce?

• Which had the longest time interval between bounces?

• Which had the lower coefficient of restitution ()?

Bounce Data

0

0.2

0.4

0.6

0.8

1

1.2

1 2 3 4 5 6

Bounce Interval

Tim

e (s

ec)

Series1

Series2

Series3

Data Collection andAnalysis

Lesson 4

The Big IdeaThe use of instruments to gather data can help us understand the impacts of

technology systems.

Compiling Our Results

Coefficient of Restitution is the time of the second bounce (T2) interval divided by the first (T1)

We will use the chalkboard to compile our information.

Coefficient of Restitution ()

Tennis Ball

Golf Ball

Data Analysis

• Were the results consistent from group to group?

• How would you explain any large variations?

• How would you explain the small variations?

Tennis Ball ()

Group 1 0.84

Group 2 0.82

Group 3 0.87

Group 4 0.65

Group 5 0.80

Group 6 0.81

Group 7 1.12

Energy Conversion

• Energy cannot be created or destroyed, but only changed from one form into another.

•The kinetic energy lost with each bounce does not disappear.

•It is mostly converted into heat energy within the ball and bounce surface while some energy is converted to sound (which we used to collect our data.)

100% PE

50% PE50% KE

100% KEJust before impact

Ball is compressedFloor is compressedNoise is madeHeat is generated0% KE 100% PE

100% KE minusenergy lost to heat and sound

100% PE70% original height

Data Collection Instruments

• Instruments can be used to collect many different kinds of data.

• Data instruments can collect physical data such as time, mass, and a tally of events.

Data Instrument

Traffic Volume Car counter strips

Demographics Census

Grocery Sales Register receipts

Wind Speed Anemometer

Data Collection Instruments

• Data instruments can also collect opinions and perceptions of people regarding a number of topics.

• Surveys– Telephone– Internet– Mail– Door to door

What makes a good survey?

• Asking the right questions

• Asking the right people

• Asking enough people

What do we want to find out?

How has cell phone use impacted our society?

Remember the “Big Idea”?

• Big Idea: The use of instruments to gather data can help us understand the impacts of technology systems.

We could ask people to describe how they think cell phone use has impacted society.

Instead, let’s focus on a more narrow question:

“How has cell phone use changed among adults in my community over the past 10 years?”

Create a Survey• Create a survey that attempts to answer

the question: “How has cell phone use changed among adults in my community over the past 10 years?”

• Include about 10 questions that are either short answer or multiple choice.

• Changes may include frequency of use, where it is used, and for what purpose (personal, business, etc)

• Type your questions into an online survey.

Conduct the Survey

• Survey at least 10 people and compile the results.

• Data will be presented in both graphical and narrative form.

• Conclusions based on the data should also be expressed.

1/5 Title and make a list

• Cell phone use has likely changed over the last three years.

• List 3 ways it might have changed– Example: # of calls per day

12/2 Title and make a list

• Will the question generate useful NUMERICAL data?

• What measurable uses will be learned from the result?

• www.yourclasspage.com/4103132507

Sample Tennis ball bounce data

• Trial 1– 0.75, 0.56, 0.37, 0.25

• Trial 2– 0.68, 0.48, 0.29, 0.21

• Trial 3– 0.71, 0.53, 0.37, 0.22

12/3 Answer in a sentence

• What trend(s) do you expect to find from our survey results?

1/6 Answer in a sentence

• Identify 3 trends that you suspect exist regarding cell phone use.– Example: People are talking more minutes per

day each year on average.– – –

10/14 Answer in a sentence

• Identify 3 ______ that you suspect exist regarding _____ ________ use.– Example: People are talking more minutes per

day each year on average.– ____________________________________– ____________________________________– ____________________________________

10/14 Warm-up – answer in short sentences

• Which ball lost the most _____ with each bounce?

• Which had the ______ time interval between bounces?

• Which had the lower coefficient of _______ ()?

Analyze the Data

• Look over the data sheet.

• What is presented?

• What trends to you notice?