What is the acceleration of a body revolving in a circle at uniform speed? a. the acceleration is zero. b. the acceleration is directed tangentially. c. the acceleration is directed toward the center. d. the acceleration is directed away from the center.

The acceleration of a body revolving in a circle at uniform speed is directed toward the center. (C)  It's called "centripetal acceleration".

The acceleration is directed towards the centre when a body revolving in a circle at uniform speed.

Option C

Explanation:

When an object w=is moving with an uniform speed, its acceleration will be constant because acceleration depends upon the velocity of the object.  Also due to circular motion, the acceleration is directed towards the center point. The tangential component of the acceleration tend to be constant in this zero.

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.