Looking at Figure 4, we observed the straight pull of the “boat paddle” produced
two rotating mass of water (vortexes) at the back (near the edge) of the moving
boat paddle. When the boat paddle was lifted out of the water, we could see the
two vortexes continued its movement (See the dotted yellow arrow at the
bottom) in the same direction of the “boat paddle”.
In the fifth experiment, (See Figure 5) using the same yellow board (paddle) in
experiment 3, we simulated a curvy hand movement. We observed that the initial
side way movement produced two rotating mass of water (vortexes). And when
the board moved inwards (See side view), the edge of the board (facing the
viewer) moved away from the vortex and we could see a new vortex formed at
the same edge of the paddle. When the paddle was lifted up, we could observed
the rotating mass of water (vortexes) continued its movement in the same
direction of the board.
purple) falling in the same direction as the red and yellow sticks within 2 seconds
after the board was lifted up from the water.