Take two Styrofoam cups, partially fill them with equal amounts of cold water, and drop equal amounts of ice into each cup to obtain a mixture of ice and water.
a. Stir the water and ice mixture in one of the cups vigorously with a nonmetallic stirrer until all of the ice has been melted. Note the time that it takes to melt the ice.
b. Set the second cup aside and observe it every 10 minutes or so until all the ice has melted. Note the time that it takes for the ice to melt.
c. How do the times compare? Where is the energy coming from to melt the ice in each cup?