You can:

select a block for testing by a mouseclick on an item from four available blocks in the upper part of the applet: two of them have the same shape and masses, and two other - same masses, but different shapes and different contact areas;
change the angle of incline;
read the values of of time which passes from the beginning of block sliding motion until the current moment of time;
start the experiment by pressing the button "Start" which releases block on the incline;
stop the motion of the block by pressing the button "Stop";
see the forces applied to the block at any given moment

Press button "Start" at different anges, notice the angle at which the block begins to slide which in accordance with the description of laboratory exercise #9 gives the upper limit on the coefficient of static friction of the given material.
make the block slide with a constant velocity by the adjustment of the angle; this gives the coefficient of dynamic friction since this value is uniquely determined by the angle. Make observations at different angles. Once the block begins to move, we read the values of time on the time gauge and evaluate the block displacement on the ramp. If it appears to you that the block moves with acceleration - change the angle and repeat the virtual experiment to achieve a constant speed of the given block on the ramp. That will allow us to find the coefficient of dynamic friction.

Applet source by Sean Russel