15 ! a certain substance is a solid at 15°c. sarah heated a sample of the solid substance in a beaker using a bunsen burner during science class. she and her partner recorded the temperature at one-minute intervals. their data is recorded in the table below. based on the girls' data, when was the kinetic energy of the substance the greatest? a) at 15° c b) at 60°c. c) when they started the heating process. d)  during the period when the substance remained at 54°c.