Question

convert a speed of 54km/h into m/s.

Answer 1

Given :
Speed=54km/hr

Conversion : 1km/hr =1000m/60x60sec=5/18 m/s

Speed=54km/h
= 54 x5/18
=270/18
=15m/s

Therefore 54km./hr speed is equal to 15m/s

Answer 2

1 kilometer is equal to 1000 meters. 
1 Hour is equal to 60 minutes. 

1 minute is equal to 60 seconds. 

Hence 1 hour is equal to 60*60 =36000 seconds 

To convert 54 km/h into m/s 

= 54 * 1000 /60 *60 

=54000/3600 =540/36 

=15 m/s 

Hence, 54 km/h is equal to 15 m/s.