The technique shown here applies to any unit conversion you may face
We normally must work using SI untis, which in thi case are m and s.
It is then necessary to know how to convert from more usual speed units, like km/h or mph, to m/s. Here is how to do:
-Converting km/h (kilometers per hour) to m /s (meters per second):
we know that 1 km = 1000m and that 1 hour = 3600 s, so:
1 km / h = 1000 m / 3600 s = 0.28 m/s
so: 1 m/s = 3.6 km / h
-Converting mph (miles per hour) to m/s (meters per second):
1 mile/ h = 1600 m / 3600 s = 0.44 m / s