277_worksheet_5

=Jan Otto 277 2013-2014=

__Me as client__ My problem with was that reading "Understanding ..." section without looking at the interactivity did not make sense for me, so I opened the interactivity window. It was perfectly looking and behaving, so I immediately understood intuitively how it works and already played with it a little. When I went back to reading, the same section "Understanding ..." was useless for me. IMHO if we make effort for making some GUI intuitive, then explaining it is non-sense (unless placing it in some additional help/manual).

Also in problem situation the formulation "on a river with a current" made me a bit confused, because it suggests there exist rivers without a current.

And last two comments about visual aspects. I didn't know what is the object in the middle, so whas not sure if it drifts or maybe have it's own motor - only when I read, I realized it is a drifting log. When I set speedBoat = speedCurrent and boatDirection = Upstream, one of the boats doesn't move. It is correct, but there is no indication that this boat participates in the animation. It could shake or give some steam or at least have a small arrow pointing the same place all the time that would suggest the boat has some nonzero speed vector in a noninertial frame of reference as it is in a state of movement.

Besides these interactivity is just perfect! Makes us familiar with the vector nature of velocity and let's us see how important is to know the frame of reference.