• To apply a force drag the red dot with your mouse.

  • With the "ground" control you can select the type of surface that the object slides across.

  • You can change the distance covered by dragging the black dot.

  • The work done by the forces is expressed with the letter W.

  • The parameters indicated are: the distance covered, the work W done by each force, the time taken to complete the displacement.

  • Always press "init" before the next observation.