GRAPHING

1
GRAPHING

• Using the following data we will look at how to
  assemble a line graph to represent the
  relationship between number of wraps of wire and
  number of paper clips picked up.

2
Our graph will be made on a grid that is 10 X
10, but any grid would work.
3
The vertical axis is called the Y axis.
The horizontal axis is called the X axis.
4
The independent variable is the data that we
control.
For example . . .
The student determines how many wraps of wire
they will use.
So, the number of wraps of wire is the
independent variable.
We will plot the independent variable on the
horizontal (X axis).
Label this axis
Number of wraps of wire
5
The dependent variable is the data that depends
on what the students does.
The student determines how many wraps of wire
they will use but, they dont know how many paper
clips the magnet will pickup.
So, the number of paper clips picked up is the
dependent variable.
Number of paper clips picked up
We will plot the dependent variable on the
vertical (Y axis).
Label this axis
Number of wraps of wire
6
Electromagnet Strength Wraps vs. Number of
Paper Clips
Place an informative title at the top.
Number of paper clips picked up
Number of wraps of wire
7
Electromagnet Strength Wraps vs. Number of
Paper Clips
Now we are ready to number the graph.
Number of paper clips picked up
Number of wraps of wire
8
First, lets go back and look at the data.
Number of wraps of wire
28
Well begin with the independent variable, the
number of wraps of wire.
The largest number we have is 28,
For the smallest number we will use 0. If we
had 0 number of wraps the magnet would pick up 0
paper clips.
So the range of numbers on the horizontal (X
axis) must go from 0 to at least 28.
9
Numbers should line up with the vertical lines .
. .
not between lines.
Number of paper clips picked up
0
1
Number of wraps of wire
10
How do we get numbers from 0 to 28 to fit on a
grid that only has 10 lines?
The lines can be any value we decide as long as
we stay consistent on an axis.
We could number our horizontal (X axis) by 1s
, but that would only get us up to 10.
We need to go to 28.
Number of paper clips picked up
0
1
2
3
4
5
6
7
8
9
10
Number of wraps of wire
11
Numbering by 2s will only take us to 20.
We do not need to end at exactly 28, and if we
number by 3s
we can take any number up to 30.
Number of paper clips picked up
24
27
30
0
3
6
9
12
15
18
21
Number of wraps of wire
12
20
Now we do the same thing with the vertical (Y
axis).
18
This axis does not need to have the same
numbering as the X axis.
16
14
For this axis we need a range that goes from 0 to
at least 19.
12
Number of paper clips picked up
If we number this axis by 2s
we can get all the
way to 20.
10
8
6
4
2
0
0 3 6 9 12 15
18 21 24 27 30
Number of wraps of wire
13
Electromagnet Strength Wraps vs. Number of
Paper Clips
20
18
16
14
12
Now we can plot the actual data.
Number of paper clips picked up
10
8
6
4
2
0
0 3 6 9 12 15
18 21 24 27 30
Number of wraps of wire
14
20
The first point will be for trial 1.
One
8
6
18
16
Locate where 8 can be found on the X axis. It
is between 6 and 9, closer to 9.
14
Locate 6 on the Y axis.
12
Plot a point on the graph where these two
lines intersect.
Number of paper clips picked up
10
8
6
4
2
0
0 3 6 9 12 15
18 21 24 27 30
Number of wraps of wire
15
Plot the points for trials 2
and 3.
20
18
16
14
12
Number of paper clips picked up
10
8
6
4
2
0
0 3 6 9 12 15
18 21 24 27 30
Number of wraps of wire
16
20
18
16
14
12
Number of paper clips picked up
10
8
We can plot a final point at 0 on the X axis
and 0 on the Y axis since zero wraps will not
pick up any paper clips.
6
4
2
0
0 3 6 9 12 15
18 21 24 27 30
Number of wraps of wire
17
Electromagnet Strength Wraps vs. Number of
Paper Clips
20
18
16
14
12
Number of paper clips picked up
10
8
6
Finally, connect the points with a line.
4
2
0
0 3 6 9 12 15
18 21 24 27 30
Number of wraps of wire
18
Electromagnet Strength Wraps vs. Number of
Paper Clips
20
18
16
14
12
Number of paper clips picked up
10
8
6
4
2
0
Nice!
0 3 6 9 12 15
18 21 24 27 30
Number of wraps of wire