How can a little kid lift a great big grown-up on a seesaw?
Look… a tiny little kid, and a great big giant, on a seesaw. The giant sits close to the middle bar. We want the kid to lift the giant up high. So here is the puzzle… where should the kid sit? Far, far out at the very end? Or close to the middle bar? Tap where you think the kid should sit… and then watch what the seesaw does!
After you watchHow can a little kid lift a great big grown-up on a seesaw?
The short answer
A tiny kid can lift a big giant on a seesaw by sitting far out at the end while the giant sits close to the middle bar. Sitting far from the middle gives the kid a long arm, and a long arm has lots of lifting power — enough to push the giant up.
The whole story
How it works
A seesaw tips toward whoever pushes down harder. Pushing-down power is not just how heavy you are — it is how heavy you are and how far out you sit from the middle bar. The middle bar is the balance point. Sit close in and you have a short arm and almost no power. Scoot far out and you get a long arm with big power. So when the tiny kid sits far out and the giant sits close in, the kid's long arm wins and lifts the giant up.
What people get wrong
Lots of kids think the heavier giant always goes down. That is only true if both riders sit the same distance from the middle bar. Move where you sit and your distance helps too, so a little kid sitting far out can lift a big giant sitting close in.
Questions kids ask
Does the kid have to be strong to lift the giant?
No! The kid does not use muscles. Just sitting far out from the middle bar gives the kid a long arm, and a long arm turns a little kid's weight into enough power to lift the giant.
What is the middle bar on a seesaw?
It is the balance point — the bar in the middle that the plank rocks on. How far you sit from this bar is what matters. The farther out you sit, the more lifting power you have.
Keep going
What else makes you wonder?
- If sitting far out gives you more power, what happens if the giant scoots far out too?
- Where else do you push far from the middle to make something easier — like a big heavy door?