• Use what you know to convert .35 km/hr to m/min

Graphing in Physics

Graphing

• A way to display data that is collected in an experiment.

• They must be constructed accurately and neatly so data is understood.

• Three main types of graphs: line, pie and bar.

4 parts of a graph1. Title & Axis

labels

2. Independent variable

3. Dependent variable

4. Scales for variable

Parts of the GraphTitle- – A statement placed

above the graph to help explain the graph.

Axis labels – give units and

description of data on each axis (side) of graph

A graph is incomplete if the title and axis labels are missing.

Parts of a Graph• The Independent Variable-

–The ONE thing in the experiment that is controlled by the experimenter.

–It usually concerns time, depth, or temperature.

–It is on the horizontal or x-axis.

Parts of a Graph• Dependent Variable

– is the variable that is directly affected by the changes in the independent variable.

–Examples of possible dependent variables: • Student grades, salary earned, number of

assignments completed

–This variable is placed on the vertical or Y-axis.

Parts of a Graph• Scales for each variable-

– In order to plot a graph you must set a scale to include all the data points.

– Scales will start at 0 and climb in equal intervals such as 2,5,10 etc.

– The scales for the x and y axis can be different. – Set the scale so that the entire space provided

is used• You want the graph to be spaced out so it is easier to

read and understand

Graphing Scientific Data • Instead of connecting the points “dot-to-

dot” style, draw in a line of best fit– a line that goes through most of the points,

but not all of them

Graphing Scientific Data • Lines of best fit allow for interpolation and extrapolation of

the data presented• Interpolation- used to approximate values that are between

data points on the graph

• Extrapolation- used to approximate values beyond the range of the data