Spreadsheet Math: Ohm’s Law

With the first unit of the year focusing on linear functions, I decided to use Ohm’s Law (a popular linear function from physics) to introduce my students to the fundamentals of spreadsheet processing. The goal of this activity is to plot a graph demonstrating a linear relation between voltage and current; their measured x- and y-values respectively. Through this process, students learn how to:

• create headers and freeze top rows
• organize and sort data into rows and columns
• plot a graph of data points
• include an equation matching a line of best fit
• share, collaborate, and even publish on a task using Google Sheets

Because lab equipment can often be unreliable or even difficult to obtain, I directed my students to use the Ohm’s Law lab simulator from the University of Colorado’s Interactive Simulations page.

After having students set the resistance to a random value of their choosing, they can then begin recording their values into a spreadsheet.

Once they have all their measurements, they can then insert a chart appropriate for the given scenario (in this case, a scatter plot).

Next they will add a trendline and select the option to include the equation for that line as well. You could have them include the r-squared value as well, which as a science teacher, I find very valuable. Since the Phet software has no variation between expected and given values however, including the r-squared value is not entirely necessary.

And that’s it; all that is left is to have the students do a quick little summary of their results and maybe direct them to analyze the relationship between the slope of their graph and resistance they set in their simulation.