Centripetal acceleration is necessary, and is present, whenever any object
moves in a closed path, or along any part of a circular path. Some examples
I can think of are:
-- a planet or a comet in orbit around the sun
-- a moon in orbit around a planet
-- the little ball making circles around the spinning roulette wheel
-- a stone tied to the end of a string, when you spin it around your head
-- the end of the spinning string on a weed-whacker
-- the tip of the blade of a fan or a windmill
-- any little bit of rubber on a car tire or bicycle tire, when they're moving
-- a strawberry seed spinning around the inside of the blender jar when you're
making a smoothie
-- a car driving around a curve in the road
-- you on almost any amusement park ride; whenever you're not moving in a
straight line, you're experiencing centripetal acceleration.
