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.

Her skin and the gymnasium floor reached thermal equilibrium.

Explanation:

Thermal energy:

It is the kinetic energy which is due to the motion of the particle. This energy can be measured in the system or object having it as in this case it is in Sienna because of high temperature and her soccer practice. Thermal energy has the ability to transfer from one object to another in the form of heat.  

Sienna on sitting the floor feels cool against her skin but after some time due to transfer of the thermal energy floor becomes hot and sienna has to shift to a different part of the floor.

Best option:

Sienna shift her position on the gymnasium floor because her skin and the gymnasium floor reached thermal equilibrium.

the solute can move "downhill," from regions of higher to lower concentration, relying on the specificity of the protein carrier to pass through the membrane. this process is called passive transport or facilitated diffusion, and does not require energy.