Question

The S.I. unit of velocity is
A. \[km\,\,{h^{ - 1}}\]
B. \[m\,\,{\min ^{ - 1}}\]
C. \[km\,\,{\min ^{ - 1}}\]
D. \[m\,\,{s^{ - 1}}\]

Answer 1

Hint: Velocity is a physical vector quantity; both magnitude and direction are needed to define it. The scalar absolute value (magnitude) of velocity is called speed. Velocity is the prime indicator of the position as well as the rapidity of the object.

Complete step by step answer:
The terms velocity and speed give us an idea of how fast or slow an object is moving. Quite often, we come across situations where we need to identify which of the two or more objects is moving faster. One can easily tell the fastest of the two if they are moving in the same direction on the same road. But if their direction of motion is in the opposite direction, then it is difficult to determine the fastest. In such cases, the concept of velocity is helpful.
Since, $velocity\, = \,\dfrac{{dis\tan ce}}{{time}}$
Hence, unit of \[velocity\, = \,\dfrac{{unit\,of\,displacement}}{{unit\,of\,time}}\]
Thus, unit of $velocity\, = \,\dfrac{m}{s}$

Thus, the option D is correct.

Note: The meaning of velocity of an object can be defined as the rate of change of the object’s position with respect to a frame of reference and time. It might sound complicated but velocity is basically speeding in a specific direction.Speed and velocity can be a little confusing for most of us. Well, the difference between speed and velocity is that speed gives us an idea of how fast an object is moving whereas velocity not only tells us its speed but also tells us the direction the body is moving in.