Speed / Velocity conversion
Most of the units of speed are compound units of distance by time, for example the SI unit Meters per second. Notable exceptions to this are Mach (a unit based on the speed of sound) and Knots (which is actually Nautical Miles per hour).
Metric countries use Kilometers per hour for road and transport whereas non-metric countries including the United Kingdom use Miles per hour.
Acceleration measurements can be converted in the same way as the corresponding speed unit.