Question

The SI unit of speed is

• A. $\raisebox{1ex}{$km$}\!\left/ \!\raisebox{-1ex}{$min$}\right.$
• B. $\raisebox{1ex}{$m$}\!\left/ \!\raisebox{-1ex}{$min$}\right.$
• C. $\raisebox{1ex}{$km$}\!\left/ \!\raisebox{-1ex}{$h$}\right.$
• D. $\raisebox{1ex}{$m$}\!\left/ \!\raisebox{-1ex}{$s$}\right.$

Answer 1

The correct option is D

$\raisebox{1ex}{$m$}\!\left/ \!\raisebox{-1ex}{$s$}\right.$

Speed:

1. Speed is measured as the ratio of distance to the time in which the distance was covered.
2. It is a scalar quantity as it has only direction and no magnitude.
3. It is directly proportional to distance when time is constant
4. It is inversely proportional to time when distance is constant

Explanation:

1. The SI unit of distance is the meter $\left(m\right)$ and of time is the second$\left(s\right)$.
2. $Speed=\frac{Dis\tan ce}{Time}=\frac{m}{s}=\raisebox{1ex}{$m$}\!\left/ \!\raisebox{-1ex}{$s$}\right.$

Therefore the SI unit of speed is $\raisebox{1ex}{$m$}\!\left/ \!\raisebox{-1ex}{$s$}\right.$.

Option D is correct