Which is a characteristic of centripetal acceleration? it is directed outward from the center of a circle. it is directed inward, toward the center of a circle. it results in an object moving faster. it results in an object moving slower.

Centripetal acceleration AND centripetal force are both directed inward, toward the center of a circular path.  That's what makes an object move in a circular path.  If the centripetal force weren't there, then there wouldn't be any centripetal acceleration, and the object would just keep traveling a straight line.

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.