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.

5 m/sec

ya the answer is 5sec..
converting 72kmph in m/sec we get 20m/sec
so 25-20=5sec/m

189km/hrs

72 km/hr == 20 m/sec .

so the diff is 25-20== 5m/sec


the final answer is 5m/sec.

18km/hour

20 m per sec

5 m/s

 A is travelling at 72km/hr = 72*1000/3600 m/sec = 20 m/sec
 B is travelling at 25m/sec= 25*3600/100 km/hr =90 km/hr
 ANS-difference  5 m/sec,18 km/hr

72 km/hr is 20m/s

Difference is 5 m/s

5 m/sec..B is 5m/sec faster then A

72kmph=72*1000m/60*60sec=20m/sec->A.
B->25m/sec
B-A=5m/sec

A is travelling at 72 k/h [Given]

=> A is travelling at 72*5/18 m/s = 20 m/s

B is travelling at 25 m/s [Given]

Therefore, the difference in their speed is 5 m/s

(1 km/hr = 5/18 mper sec)
so that, 72 km/hr=20mtr/sec
A's speed will be 20m/sec and B's speed will be 25 m/sec

hence the diff.of speed between them will be of 5 m/sec

Step-1
Convert the speed of A in meter per second.
As 1km=1000meters and 1hour = 3600 second
    => 72km/hour =72x1000
                               60x60
                            =20meter/sec
Step-2
Now we can substract the speeds of A and B
 Difference in speed= Speed of B- Speed of A
                               = 25-20
                               =5meter per second
Hence speed of B is more than A by 5m/s
                                     

Change the meters into kilometer and sec into hrs after that equalize these two answers.

1 meter/sec is the difference b/w the speeds

Answer is 5m/s
when 72 converted to m/s becomes 20
and 25-20 = 5

72 km/hr = 72* (5/18) m/sec = 20 /sec
 so difference is 25 - 20 = 5 m/sec

SPEED OF B= 25*60*60/1000=90km/hr
SPEED DIF.= 18

To convert km/hr to m/s use 5/18

72*5/18=20m/s
25-20=5m/s

5m/sec...

1 m/s