First off, I'd advise you to rotate the camera up and to the right so you're looking
more down and at an angle.
Then press the "GO" button. A block will move from the origin, (0,0,0), to the point
(5,4,3). The speed on the block is uniform. As it does this "shadow" blocks move
along the x-, y-, and z-axes, keeping aligned with the main block. The speeds
of the shadow blocks are less than that of the main block, but the 3 components
of the velocity vector of the main block are just the 3 speeds of the shadow
blocks. The speed of the main block (a non-negative scalar) is the square root
of the sum of the squares of its components.