How Fast is the Postal Service?

In our group, Donald came up with the grand idea of sending a stop watch in the post. We thought about the equation Speed = Distance / Time. So if we know the distance we are sending the watch and how long it took to get there, we can work out just how fast or slow the postal service actually is.

Yesterday I made a box for the stopwatch but after finding out it was too high to fit through a letterbox I remade it today and sent it off with some quick instructions - making sure i started the stopwatch before I sent it!