This Demonstration calculates the motion in time of Kermit's legendary What-Happens-Next-Machine from Sesame Street. A mass is dropped onto a seesaw. The seesaw pulls a rope that opens the lid of a box, from which a balloon is freed that switches on a radio. Quite entertaining, but unfortunately for the physicist on Sesame Street, bugs and breakdowns flaw the performance. Here a functioning machine is simulated. You can also try out which masses, heights, and lever lengths cannot free the balloon.
Of course, do not touch any controls once you have clicked the trigger. Resetting the timer before changing parameters makes sense. Attention: too large a time step will make nonsense of the calculation.
A longer lever on which to drop the sandbag is not necessarily a better way to pull up the lid of the box. For more details, see the preprint: "Kermit's What-Happens-Next-Machine Reloaded".