Question

Express the following speeds in m/s.
(a) 45km/h
(b) 135 km/h
(c) 90 km/h
(d) 75km/h

Answer 1

We know:

1 km = 1000 m
1 h = (60 $\times$ 60 ) s = 3600 s

Now,

(a) 45 km/h = (45 $\times$ 1000)/(1 $\times$ 3600)
= 12.5 m/s

(b) 135 km/h = (135 $\times$ 1000)/(1 $\times$ 3600)
= 37.5 m/s

(c) 90 km/h = (90 $\times$ 1000)/(1 $\times$ 3600)
= 25 m/s

(d) 75 km/h = (75 $\times$ 1000)/(1 $\times$ 3600)
= 20.83 m/s