An object traveling in a circle, even at constant speed, is accelerating. That's because its direction is constantly changing to point to the center of the circular path — a condition that's defined as *centripetal acceleration*, as expressed in the equation here. When this acts on mass objects, it generates centripetal force.

With the same Latin root as *pedal*, the suffix -*petal* translates to __ftraveling__ — **centripetal force** is a “center heading” force. Electromagnetic forces, nuclear forces, and even gravity (in bodies orbiting in space and on Earth) can keep objects on circular paths by acting as centripetal-force sources.

With the same Latin root as *fugitive*, the suffix -*fugal* translates to __fleeing__ — **centrifugal force** is a “center fleeing” force. This is a pseudoforce, an equal but opposite reaction to centripetal force (according to Newton's Third Law) so practical calculations generally only derive centripetal force.