Density of Soap

Laboratory 01 in SC 130 Physical Science focused on the linear relationship between volume and density for soap. Harmony beauty soap with a density greater than one gram per cubic centimeter was used along with Ivory soap with a density of less than one gram per cubic centimeter. The soap was carved into square chunks so the volume could be calculated from length × width × height.

LA masses a chunk of soap.

The laboratory begins with a quote from Freeman Dyson that notes that nature obeys mathematical calculations.

Jeanine masses soap while Pertin records the data.

Latoya and Leslie inspect their carving handiwork.

During the regular term the class moves to the computer laboratory for the second half of the laboratory. During the summer this is not possible. The class hand graphs the data and then enters the data into a scientific calculator to calculate the slope and intercept. The linearity of the equation mass = density × volume is determined from an analysis of whether the points form a straight line.

The result is then used in a group discussion at the end of the class to make a prediction as to whether the soap will float or sink. Each group is asked to commit to a prediction.

Then the prediction is tested by dropping the soap chunks in a beaker of water. If all has gone well, the soap will obey the mathematically predicted result. Somehow the soap knows what to do. Nature is mathematical.