Question

6b. explain how the kinetic energy of the molecules in the instant hot pack and in the cold bench will change as a result of the heat transfer you modeled in part 6a.

Explanation:

Heat transfer occurs from the hot pack (higher temperature) to the cold bench (lower temperature). Kinetic energy of molecules is related to temperature (higher temp means more kinetic energy). So, molecules in the hot pack lose heat, their temperature decreases, so their kinetic energy decreases. Molecules in the cold bench gain heat, temperature increases, so their kinetic energy increases.

Answer:

When heat transfers from the instant hot pack to the cold bench (as in 6a, assuming heat flows from hot to cold), the molecules in the instant hot pack lose thermal energy. Since kinetic energy of molecules is related to temperature (higher temperature means greater average kinetic energy of molecules), the temperature of the hot pack decreases, so the kinetic energy of its molecules decreases. Conversely, the cold bench gains thermal energy, its temperature increases, so the kinetic energy of the molecules in the cold bench increases.