Centrifugal force is the outward pull you feel when something spins or turns quickly. When you're on a merry-go-round, you feel pushed toward the outside edge, away from the center. When a car takes a sharp turn, you feel yourself pressed against the door. That sensation is often called centrifugal force.

Here's what's really happening: your body wants to keep moving in a straight line (that's called inertia), but the spinning platform or turning car forces you to move in a circle instead. The conflict between your body's desire to go straight and the circular motion creates that outward pull.

Scientists sometimes discuss whether centrifugal force is a “real” force or just the effect of inertia, but the sensation is certainly real. Engineers use centrifugal force in many practical ways: washing machines spin clothes to fling water outward through tiny holes, and centrifuges in laboratories spin test tubes so fast that heavier materials get pushed to the bottom while lighter materials stay on top.

The opposite is centripetal force, which pulls inward toward the center and keeps spinning objects from flying off.