Applet shows a rod moving away from a wall. In one case it is being dragged with a constant velocity and in the other the rod is allowed to slip.
Motion of the upper end is with an increasing velocity in both the cases and the midpoint of the rod moves along a circle centered around the corner.
Note that when the rod is allowed to slip, the lower end is also accelerating.
The point through which the instantaneous axis passes can be displayed by clicking on the menu bar. This point is displayed as a white dot. Any point on the rod can be imagined to be rotating about this point. If you wish to determine the velocity of a point on the rod all you need to do is draw a line from the white dot to the point on the rod. This is shown as a white line. The velocity of the point on the rod will be at right angles to this line. The point whose velocity vector you want displayed can be shifted by left or right clicking in the applet area.