aim: how to plot or graph data. what is the scientific method? “the road to knowledge” the...

Aim: How to plot or graph data

What is the Scientific Method? “The Road to Knowledge”

•The Scientific Method is a method of procedure scientist use consisting in observation, measurement, and experiment, and the formulation, testing, and modification of hypotheses.

•It is a way to ask and answer scientific questions by making observations and doing experiments

•It is a dynamic process; meaning, there is no definite order to the steps in the scientific method. Scientist jump from one step to another when testing a hypothesis, even formulating a new one.

Steps to the Scientific Method•Making observations

•Coming up with a hypothesis and testing it. A hypothesis involves developing an idea or set of ideas that might explain our observations

•Collect and analyze data.

•Check results in experiment against your hypothesis: “Do your results agree with your hypothesis?”

•Start over if you need to.

Graphing and Analyzing Data•Identify dependent and independent variables•Dependent variable – the variable that is being observed during an experiment. •Independent variable – the variable that is being changed during an experiment

Graphing and Analyzing Data Cont.•Labeling the graph• Title the graph• Label the y-axis (dependent variable) and x-axis (independent variable)

•Direct relationship; “as one variable increases, the other variable increases” or “as one variable decreases, the other variable decreases”•Indirect or inverse relationship; “as one variable increases, the other variable decreases” or “as one variable decreases, the other variable increases”

Determining slope of best-fit line 1. Prepare a scatter plot of the data. 2. Using a ruler, draw a straight line (best-fit line) so that the plotted points are as close to the line as possible.

3. Find two points that you think will be on the "best-fit" line.

4. We are choosing the points (1.4, 100) and (3.4, 300). You may choose different points.

5. Calculate the slope of the line through your two points. , x1= 1.4 and x2= 3.4

Y1 = 100 and Y2= 300

Length (cm)Mass (g)5.25 0.48.25 0.6

18.75 1.222.25 1.424.75 1.6

24.8 1.616 1.1

9.2 0.723 1.4

11.5 0.83.2 0.12.5 0.05

0 5 10 15 20 25 300

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

Length (cm)

Mas

s (g)

Mass versus Length of Spaghetti