Your answer is cumulonimbus clouds
Answer:
As an object moves in a circle, it is constantly changing its direction. ... Accelerating objects are objects which are changing their velocity - either the speed (i.e., magnitude of the velocity vector) or the direction. An object undergoing uniform circular motion is moving with a constant speed.
The lens equation gives d relation between focal length, object distance n image distance.
1/f = 1/v + 1/u
seldon