There is a little gem hidden in Google: the calculator. This gadget is capable of assisting students and teachers in a lot of the otherwise tedious calculations in introductory physics.1 Figure 1 gives a little example of what the calculator can do, determining the Bohr radius based on a number of other physical constants.
The reason this tool is hidden is that it only comes up when correct mathematical expressions are entered, which is something that people rarely even try. Figure 2 shows another example from a typical undergraduate physics problem where a proton is accelerated from an initial speed in a potential difference. As can be seen, the calculator only “kicks in” if the expression has the correct mathematical form and physical dimensions; otherwise, Google “silently fails” and just delivers related search results.
Students tend to be surprised when this little gem is first demonstrated in class, and...