Where does the refraction occur when the light enters a different medium?

Explanation:

The speed of light when it travels through glass, diamond, etc, the light travels at different speed from the speed of light. Speed of the light in material is related to the index of refraction.

Hence, light have different speeds in different medium and also, will have different wavelength in different mediums.

The change in speed which occurs when the light passes from one medium to the another is responsible for bending of the light which is called as refraction.

Further, if the light travels from a low denser medium to high denser medium, it refracts towards the normal and if the light travels from high denser medium to low denser medium, it refracts away from the normal. The refraction of light happens at the point of incidence.

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.