June 2009 - University of Hertfordshire

Water pressure
Getting the best from PowerPoint: 2 and 3-dimensional animations
25
Multiple Movements
The slide below may appear at first sight to be a more complex animation than the
previous one, but it is in fact rather simpler. The slide illustrates how fluctuations in water
pressure at the base of a glacier can be measured by installing a pressure sensor in a
borehole drilled to the base of the glacier. As water pressure rises and falls, the level of
water in the borehole rises and falls and the resultant pressure change is monitored by a
pressure sensor suspended in the borehole that outputs a signal recorded by a
datalogger. The image of the datalogger provides a visual prompt for the teacher, while
the black disc moving along the graph illustrates how the signal output from the
transducer will change as water level in the borehole changes.
The creation of this animation is very simple. The water level rising and falling is simply a
blue rectangle moving along a vertical motion path, grouped with the two arrows that
follow horizontal motion paths. The black disc follows a custom motion path that has been
superimposed on the graph and is set to run „with previous‟ (i.e. with the movement of the
blue rectangle and arrows) and as before, all motion is set to continue until the end of the
slide.
Time
Blended Learning In Practice June 2009