Question

sienna is at soccer practice. she has just finished running two miles, and is very warm. the temperature outside is 95°f, and sienna is beginning to feel overheated. her coach takes her into the gymnasium and tells her to sit down on the floor and relax for a few minutes. sienna notices that the floor feels cool against her skin. after a few minutes, however, the gymnasium floor no longer feels cool, and sienna has to shift to a different part of the floor. why did sienna shift her position on the gymnasium floor? thermal energy was transferred from the gymnasium floor to her skin. her skin and the gymnasium floor reached thermal equilibrium. thermal energy was transferred from the air to her skin. her skin and the surrounding air reached thermal equilibrium.

Explanation:

Thermal energy transfer occurs until thermal equilibrium is reached. When Sienna sat on the floor, thermal energy was transferred from her warm skin to the cooler floor. After some time, her skin and the floor reached thermal equilibrium (same temperature), so the floor no longer felt cool. She then had to shift to a different (cooler) part of the floor. The first option is incorrect as thermal energy was transferred from her skin to the floor, not the other way around. The third option is about air - which is not relevant to the floor - skin interaction described. The fourth option is also about air - skin, not floor - skin.

Answer:

Her skin and the gymnasium floor reached thermal equilibrium.