Question

If a is travelling at 72 km per hour on a highway. B is travelling at a speed of 25 meters per second on a highway. What is the difference in their speeds in m/sec.

Answer 1

A speed is 72 km/hr = 72*5/18 m/s = 20 m/s

B is traveling at 20 m/s

Thus,

Difference in their speeds = 5 m/s

Remember,
to convert speeds from km/hr to m/s multiply the km/hr speed by 5/18
And multiply by 18/5 to convert from m/s to km/hr.

Answer 2

If A is Traveling 72km/hour then its metre pre second is:-

1 km=1000m then, 72 km=72000 m and

1 minute=60 sec then 1 hour (60min)=3600 sec

72000m/36000= 20

and B is traveling 25 meters per second

so difference is 25-20 =5 m/s