Students conducted an experiment to determine the insulating properties of certain materials. In each trial, "blankets" made of different materials of different thicknesses were wrapped around an aluminum capsule filled with 0.250 L of water at a known initial temperature, Ti, and placed into an oven preheated to a certain temperature. Heat was transferred through the insulating materials from the oven to the water inside the capsule. After 5 minutes, the temperature of the water inside the capsule, Tf, was recorded. The heat flow, measured in joules per second (J/s), is shown in Table 1.
(Note: In each trial, the same size and shape of aluminum capsule were used. One trial was done with no insulation around the aluminum capsule.)