Graphing | What your graphs mean | Graphs that we did


Graph Meaning

So, what does the graph really mean?

points connected with a line

The line that you drew -- the time-temperature curve -- is a picture of what happened during the experiment.

You could also have written down your temperature readings as numbers on a scrap of paper. But a graph gives you a picture that is easier to understand. Can you tell what happened in this experiment by looking at the graph?

You can see that the temperature rose steadily for a period of time, up to a certain point, then the termperature fell. The shape of the graph and the slope of the lines tells the story of the experiment.

So if you're trying to compare this stage of the Energy House witha different stage, you want to compare the graphs of the experiments. You want to put the graphs together.

tracing paper overlay for transfering graphs

An easy way to transfer your graphs is with tracing paper or carbon paper.

What if you drew the graphs for two experiments on one piece of graph paper?

Then it would be very easy to see the difference between the two experiments.

HINT: Graph each experiment in a different color. That way it's even easier to see the differences.

IMPORTANT!!! Make sure that you line up the graphs exactly, so that the time and temperatire scales are the same for every experiment.

double graph of two experiements

What does this double graph say? (Hint: the red dots show higher temperatures than the green dots, which are lower on the Temperature scale.)

In the Red experiment, the Energy House got warmer than in the Green experiment, and stayed warmer longer, right?

the meaning of the area under curves

The meaning of the Area of the Curve...

You can even tell how much more heat stayed in the Energy House in the Red experiment. How do you do that?

Just count all the squares under each curve!

The number of square under the red curve is the total units of heat saved in the Red experiment. The number of squares under the green curve is the total units of heat saved in the Green experiment.

So, the red squares minus the green squares equals the difference between the two stages of the Energy House in the Red and Green experiments.

 the meaning of the slopes of curves

The meaning of the Slope of the Curve...

Look at the slope of the lines of your graph. Notice how steeply sloped the lines are. Do you think this means anything?

A steeply sloped line means heat is gaining or losing faster.

A more shallow-sloped line means heat is not losing or gaining quite so fast.

Can you tell which line shows the heat going out of the Energy House more slowly?

ANSWER: The Red line shows heat is being lost more slowly than the Green line.


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