Question

Express each of the following in m/s.

(a) 1 km $h^{-1}$ (b) 18 km $mi{n}^{-1}$

Answer 1

(a) 1 km/h

We know

1 km = 1000 m

1 hour = 3600 sec

So, $1km{h}^{-1}=1\times \frac{1000}{3600}=\frac{5}{18}$ m/s

(b) 18 km/min

We know,

1 km = 1000 m

1 min = 60 sec

So,$18km{min}^{-1}=18\times \frac{1000}{60}=300$ m/s