Vectors (A+70)

  A+70+0 X,Y,Z-coordinate system with vector arrows.
  A+70+5 Vector arrows of various sizes and colors fit in wooden bases.
  A+70+10 Relative velocity: Three electric cars on tracks make chalk line.
  A+70+20 Rope with slug(unit of mass) in center is lifted from ends.
  A+70+25 Film loop: "Vector addition: Velocity of a boat", 3:35 min.
  A+70+30 Applet: Ship Traveling in a Current