express a speed of 30m/s in km/h
The given speed is 30 m/s.
⇒ Distance travel by object in 1 sec = 30 m
∴ Distance travel by object in 3600 sec or 1 hour = 3600 × 30 m
⇒ Distance travel by object in 1 hour = 108000 m
⇒ Distance travel by object in 1 hour = 108000/1000 km
⇒ Distance travel by object in 1 hour = 108 km
∴ Speed of object = 108 km/hr