Graphing

Independent vs. Dependent In an experiment, the variable that YOU change is the Independent Variable In an experiment, the variable that YOU change is the Independent Variable The variable that you measure is the Dependent variable The variable that you measure is the Dependent variable EX: We are going to grow bean plants over the next few weeks. EX: We are going to grow bean plants over the next few weeks.

Quantitative vs. Qualitative Quantitative – something you observe or measure using numbers – Quantitative – something you observe or measure using numbers – EX: he is 6 ft tall EX: he is 6 ft tall Qualitative – something you observe or measure using descriptions only – Qualitative – something you observe or measure using descriptions only – Ex:he is tall Ex:he is tall

Data Tables Time(seconds)Distance(meters) Straight lines drawn with a ruler Independent Variable Dependent Variable Units

Or like this…. Time(seconds) Distance (meters) Straight lines drawn with a ruler Independent Variable Dependent Variable Units

Types of Graphs Bar Graph Bar Graph Qualitative vs. Quantitative Qualitative vs. Quantitative Line Graph Line Graph Quantitative vs. Quantitative Quantitative vs. Quantitative Circle Graph Circle Graph Percentages Percentages

Rules for Graphing You MUST use graph paper and a ruler!!! You MUST use graph paper and a ruler!!! The independent variable is on the X-axis The independent variable is on the X-axis The dependent variable is on the y-axis The dependent variable is on the y-axis DRY MIX DRY MIX DRY – Dependent, Responding, Y-axis DRY – Dependent, Responding, Y-axis MIX – Manipulated, Independent, X-axis MIX – Manipulated, Independent, X-axis

The axes should be labeled with the measured quantity and the unit in which it was measured. Use Both!!!

Scales on the axes should be appropriate for the data, spread out as much as possible, and the axis must be divided evenly giving each square the same value.

Title should be in Y-axis vs. X-axis format Density of water vs. Temperature of water

TAILS T itle T itle A xis A xis I ntervals I ntervals L abels L abels S cale S cale

Is there a relationship between thumb length and number of wins? Independent Variable? Independent Variable? Thumb length Thumb length Dependent Variable? Dependent Variable? Number of wins Number of wins Thumb Length (mm) Number of Wins

Is there a relationship between thumb length and number of wins? Thumb length (mm) Number of Wins Thumb Length (mm) # of wins # of wins vs. thumb length ** Use this if we are comparing the number of wins

Is there a relationship between thumb length and number of wins? Thumb length (mm) Number of Wins Thumb Length (mm) # of wins # of wins vs. thumb length ** Use this if we are looking for a trend in the number of wins

Extrapolation: Extrapo – huh?? Extrapo – huh?? Extrapolation – using a graph to make an estimation outside the known range. Extrapolation – using a graph to make an estimation outside the known range. Example please…. Example please….

Physical science students poured liquid into a graduated cylinder and measured the mass of several pre-determined volumes. Use your graph to predict the mass of 23 mL of liquid 1. Draw a line of best fit: a straight line that encompasses as many points as possible. 2. Draw a line up from 23 until it reaches the line of best fit. 3. Draw a line over to the y-axis and read the measurement. 4. The mass of 23mL of water is approximately 79.0 grams. 5. Why doesn’t the line of best fit go through the origin? 1. The container that holds the liquid has mass

Interpolate So the opposite of extrapolate is…. So the opposite of extrapolate is…. INTERPOLATE! INTERPOLATE! using a graph to make an estimation within the known range using a graph to make an estimation within the known range This process is very similar to extrapolating. This process is very similar to extrapolating.

Physical science students poured liquid into a graduated cylinder and measured the mass of several pre-determined volumes. Use your graph to predict the mass of 10 mL of liquid 1. Draw a line of best fit: 2. Draw a line up from 10 until it reaches the line of best fit. 3. Draw a line over to the y-axis and read the measurement. 4. The mass of 10mL of water is approximately 61.0 grams.

Start a New Page… BARBIE BUNGEE JUMP!!

Purpose: To use EXTRAPOLATION to provide a THRILLING, yet SAFE, jump from the top of the bleachers (4.6 m). Note: “Thrilling” is.5 m or less than from the ground!! less than from the ground!! Problem: What is the relationship between the drop distance and the number of rubber bands used to make the bungee cord? Identify independent, dependent and controlled variables. Hypothesis: (An “If… then...” statement) Materials: Barbie, meter stick, rubber bands

Procedure: 1. Use one rubber band to secure Barbie’s ankles together and to serve as a point of attachment. Use another rubber band to secure hair and arms 2. Construct a bungee cord composed of 2 rubber bands and attach to Barbie’s ankles. 3. Barbie will fall freely from a standing position, plunging head first. Test drop Barbie 3 times to practice taking measurements. 4. Drop Barbie 3 times and record measurement 5. Add 1 rubber band to your attached bungee cord. Drop Barbie three times and record the data. 6. Repeat step 4 and 5 until you have a total of 6 rubber bands. Record data each time. 7. Calculate the average and round to the nearest.01 m. Record in the data table.

# of rubber bands Length of bungee (meters) Drop distance trial 1 (meters) Drop distance trial 2 (meters) Drop distance trial 3 (meters) Average(meters)

Fill in the following on your lab: IV IV DV DV Constants Constants Hypothesis: If/Then….. Hypothesis: If/Then….. Draw the Axes on your graph Draw the Axes on your graph

Turn in your graphing packet!!! Turn in your graphing packet!!! Double check to make sure everything is there Double check to make sure everything is there Analysis: Analysis: 1. Graph your average drop height vs. number of rubber bands 2. Use your line of best fit and predict how many rubber bands would be needed to allow Barbie a successful, yet thrilling, jump from the top of the bleachers (5.4 meters). – write this in your lab!! Prediction: ________________ Prediction: ________________ Result: ___________________ Result: ___________________

Monday, September 13 Answer the following in your notebook:  Conclusion: 1. How did you use your graph to make the prediction of the number of rubber bands for a jump from the bleachers? 2. How did your result compare to your prediction? 3. Why do you think the results turned out the way they did? 4. Is the origin (0,0) a valid point (meaning will the line go through it)? Why/why not?  Glue in your hand drawn graph. Make sure it has labels and a title!!

Graphing Test You have a graphing test Wednesday. You will be asked to create two data tables and to graph the data on those tables. You may use your science notebook. Make sure it is ready to go!! Do not forget to bring it to class. You have a graphing test Wednesday. You will be asked to create two data tables and to graph the data on those tables. You may use your science notebook. Make sure it is ready to go!! Do not forget to bring it to class.

Barbie Bungee Jump – Part 1 Purpose: To ensure a safe and thrilling jump, you will determine the relationship between the drop distance and the number of rubber bands to make the bungee cord. Purpose: To ensure a safe and thrilling jump, you will determine the relationship between the drop distance and the number of rubber bands to make the bungee cord. Materials: Barbie, meter stick, rubber bands Materials: Barbie, meter stick, rubber bands Procedure: Procedure: 1. Use one rubber band to secure Barbie’s ankles together and to serve as a point of attachment. Use another rubber band to secure hair and arms (see teacher demonstration). 2. Construct a bungee cord composed of 2 rubber bands and attach to Barbie’s ankles. 3. Barbie will fall freely from a standing position, plunging head first. Test drop Barbie 3 times to practice taking measurements. 4. Drop Barbie 3 times and record measurement 5. Add a rubber band to your attached bungee cord. Drop Barbie three times and record the data. 6. Repeat step 4 until you have a total of 6 rubber bands. Record data each time. 7. Calculate the average of the data and record.