Plz what is speed distance per time(miles perhour or meters per second) distance(miles or meters) time per distance(hours per mile or seconds per meter) time(hours or seconds)

The definition of speed is (distance covered) / (time to cover the distance) .

So a unit of speed has to be (a unit of length) / (a unit of time) .

Here are several perfectly fine units of speed:

-- miles per hour

-- feet per second

-- meters per second

-- kilometers per hour

-- inches per second

-- centimeters per minute

-- yards per Century

-- furlongs per fortnight

-- nanometers per microsecond

-- Smoots per week

-- parsecs per millenium

that would be because of both gravity and friction. so     c