Why does a pendulum swing?
Compare a short string with a long one
Down and up again
Let's move the ball on the string to the side and let it go. The ground pulls him down, so he accelerates to the lowest place.
But there the ball does not stop immediately: it is already moving. By inertia it rises to the other side, slows down and returns.
This is how the swing happens. The thread holds the ball near the support and prevents it from flying straight away.
The long pendulum is slower
Let's extend the thread and tilt the ball at the same small angle. Now it moves in a wider arc.
One round trip takes longer. The long pendulum swings slower than the short one.
It is the length that helps change the rhythm here. We did not change the ball itself and did not push it while swinging.
Everyone has their own rhythm
Let's release both balls at the same time. At first they walk together, but soon the short one begins to return earlier.
While the long pendulum makes one swing, the short one manages to move further along its next swing.
Gradually both calm down: air and friction take away part of the energy of movement. To pump further, you need a new push.
For adults · discuss together
Small scope. The length of the thread affects the swing time. The movement is a little slow and gradually subsides.
Before experience
Ask: “What do you think will happen?” Let the child check his guess first.
After the experience
What has changed? What remains the same? Where can you notice a similar phenomenon?
