If we are speaking about a constant speed, it is defined as a distance traveled divided by a time spent. In the given problem, the distance is given `(D = 19` miles) and the time `T` = `3` hours and` 48` minutes is given, too. But for division we have to transform the time into some single units, for example to hours.
There are `60` minutes in one hour, therefore `48` minutes is equal to `48/60 = 8 / 10 = 0.8 (hours),` so `T = 3.8` hours. Thus the speed `V = 19 / 3.8 = 5` (miles / hour). Actually this value may be the answer, but we also may want this speed to be expressed in, say, standard meters per second.
To perform this conversion, recall that `1` mile `approx 1609` meters and `1` hour = `3600` seconds. Therefore `V approx 5*1609/3600 approx 2.2 (m/s).`
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