# Michiko walked a distance 1.60 km in 30 m. What was her average speed in m/s?

Mar 25, 2018

$0.89 \setminus \text{m/s}$.

#### Explanation:

Well, she walked $1.6 \setminus \text{km}$ in $30 \setminus \text{min}$, and so her speed in $\text{km/h}$ is:

(1.6 \ "km")/(30 \ "min")=(1.6 \ "km")/(0.5 \ "h")=3.2 \ "km/h".

The magical number, as I call it, is $3.6$, which converts $\text{m/s}$ into $\text{km/h}$. Know that, $1 \setminus \text{m/s"=3.6 \ "km/h}$.

And so here, the speed in meters per second is:

$\frac{3.2}{3.6} \approx 0.89 \setminus \text{m/s}$.