During cooling, the kinetic energy of the molecules falls. why does this happen?

The correct answer of this question is : Molecular motion or vibration slows down

EXPLANATION :

The kinetic energy of the molecule depends on the molecular motion. Molecules might have different types of kinetic energy depending on the type of substance i.e solid,liquid or gases.

During cooling, we are reducing the temperature of the substance. Due to the decrease of temperature, the molecular speed is also decreased. It is so because the molecular speed is dependent on the temperature of the substance.

Hence, the vibration, rotation or translation motion of the molecule slows down during cooling, which in turn, decreases the kinetic energy of the molecule.

answer: the exterior temperature of commercial jet planes as they leave the stratosphere and return to the ground increases steadily.

explanation:

the lower most layer of atmosphere is troposphere which extends from 0 to 12 km above the surface of the earth. the temperature initially decreases as distance is increased from the earth's surface. commercial jets fly in lower part of the stratosphere. the stratosphere extends upto 50 km. the temperature in stratosphere starts rising again due to presence of ozone which traps the uv rays.

thus, when the planes leave the stratosphere and return to the ground, the exterior temperature increases steadily.

a electromagnetic waves