I understand what you mean now.
The simulation allow user to change the unit for initial velocity(km/h, m/s or mile/h).
However, the braking distances and the distance due to reaction time are all expressed in meter.
The braking distance is 25.51[b]m[/b] when the friction coefficient is 0.8

The mile/h was added due to request from one of the user, so I added that item in the selection list.
But I did not change the unit in the simulation from [b]m[/b] to [b]ft[/b]. That is why the number is the same, if you just changh the unit.

I just found out from the code that there are two parameters for the applet
<param name="european" value="no">
<param name="feet" value="no">
The "." in the displayed number field will be switched to "," if the value for "european" is changed to "yes".
And the unit in the simulation will be changed from "m" to "ft" if the value for "feet" is changed to "yes",too.