Inertia everywhere

Experiment 1b

Install the experiment again as ahown in the photo. But this time you move the cardboard carefully and slowly at first, and then a bit faster and faster and suddenly you stop.
Before you execute the experiment, make an assumption about the result of it.

If the experiment does not work well, use the following trick: Push the ball a little bit into the cardboard, so there is a little dent. The dent prevents the ball from rolling away right at the start.

What will happen with the ball, if the cardboard is starting to move slowly at first and then faster and faster?

a) The ball will stay where it is again because of its inertia. The cardboard will move away under the ball.

b) The ball will stay on the cardboard this time und will move with it. If the cardboard has been stopped, the ball moves on.