Using a Spreadsheet to Simulate an experiment
Another way that we can use a spreadsheet is to produce a model of a physical
phenomena. This is particularly useful when it is not possible or unethical to conduct an
experiment. A good example of this is the models used to design safety features in
motorcars. You can't test these features by crashing real cars with real people in them
(although you can use the data collected after accidents) so computer models are used
instead. Another example are the models used to predict climate change, experimenting
with the weather would simply take too long and would also be ethically problematic.
How the models work for these two examples is however way beyond the comprehension
of the average IB students and their teachers. In this course we only need to introduce the
concept with some simple examples.
Loading a Truck
This is a simple example to get the idea across. Consider a truck in the process of being
loaded with sand. 100kg of sand are loaded into the truck every minute but at the end of
each minute 10% is removed.
The question is when (if
ever) will equilibrium be reached and how much sand will the truck contain? It is of
course possible (and not that difficult) to work out the answer without a spreadsheet but
that's not the point of the exercise. The assignment is to make a spreadsheet to find the
answer. If students have already used a spreadsheet to analyse their data obtained from
practicals they will already know how to write equations and propagate them down a
column. Below is an example of how the spreadsheet might look.
