Here is an animation of a mass-spring system where the mass slides horizontally on a steadily moving conveyor belt.
The contact between the block of mass and the belt is of the dry friction kind (Coulomb's friction). Consequently the block periodically sticks to the belt and moves forward with it until the force of the stretching spring overcomes the force of friction and yanks it back, making it to slip against the belt. In the animation the block is shown in a dark color while slipping, and a light color while sticking.
The fully executed Maple worksheet can be slow to load and requires a good deal of memory. Therefore I have attached two versions which are identical in all respects except that in one of them I have removed the Maple output to make is easy to load if your computer has limitations.
Download worksheet (no Maple output) block-sliding-on-conveyor-belt-stripped.mw
Doiwnload worksheet (with Maple output) (sorry, exceeds MaplePrime's size limit)