Question

If a train travels $1600{\text{ km}}$ in $16$ hours, how fast is it moving?

Answer 1

Hint : In order to judge or find how fast an object or a vehicle is moving, we have to find the speed of that object. One can easily comment looking at the speed of the vehicle rather than the distance covered in given time. Vehicle having more speed is said to be faster than that having low speed.

Complete Step By Step Answer:
Speed is said to be the rate of change of position of an object in any direction or we can say that it is the magnitude of the rate of change of position and thus by this we can understand that speed is a scalar quantity.
As to find the speed of the train above, we have to finds it rate of change of position which is given by,
${\text{Speed = }}\dfrac{{{\text{Distance}}}}{{{\text{Time}}}}$
Given the data as ${\text{distance = 1600 km}}$ and time taken $16$ hour, speed of the train will be,
${\text{Speed = }}\dfrac{{1600}}{{16}}{\text{ km/h}}$
${\text{ = 100 km/h}}$
As the speed of the train is ${\text{100 km/h}}$ , we can say that it is moving very fast.

Note :
It is good to note that the S.I unit of speed is ${\text{meter/second}}$ but as the units given in the problem were kilometer and hour, we calculated our speed in the same.
Other than this one should remember that a quantity is said to be scalar if it does not depend on the direction, those quantities which are dependent on direction are said to be vectors.