Block sliding into a friction patch

Initial conditions :

Description : There is a friction patch (indicated by that green patch in the middle of the screen). You can set the initial speed, the coefficient of kinetic friction, the length of the patch, and the mass of the object (don't forget to UPDATE when you change one of the values). During the motion on the friction patch, the acceleration is indicated below the friction patch. Throughout the motion, the velocity of the object is indicated above it. [The "center" of the red block is where you should measure the positions (the "x") .. that's where the forces will act. Notice that the acceleration doesn't start until that middle of the block is touching the friction patch. Also, the "origin" for X is at the start of the friction patch.]

There is a faint possibility that the mass will "jump" erratically at the end of the motion (if it "stops" on the patch) ... sorry about that, just hit the "step back" button once to bring it back to the true stopping point. {I think I have fixed the bug, but you might hit a combination that I haven't tried.}