Centripetal and Centrifugal Force Explained Simply
If you swing a ball on a string in a circle, two "forces" seem to be at play - but only one of them is actually real.
đź’¬ Mia asks Grandpa Theo
When I swing a ball on a string in a circle, the ball pulls outward. Is that the centrifugal force?
It feels that way, but it's actually the opposite: the string is constantly pulling the ball inward, toward the center - that's the real force, the centripetal force. Without it, the ball would simply fly off in a straight line.
So what's the centrifugal force I think I feel then?
That's just a fictitious force - your body actually wants to keep flying straight (inertia), and because the ball keeps turning sideways, it feels to you like you're being pushed outward. Seen from the outside, this force doesn't really exist at all.
In a car going around a curve, it seemingly "pushes" you outward against the door - that's the felt centrifugal force. In reality, the seat/seatbelt holds you on the curve's circular path with a real force (centripetal force).
Physicists call the centrifugal force a "fictitious force" or "inertial force" for exactly this reason - it only shows up when you view the motion from the rotating object's perspective, not from the outside.
← Back to overview