Question

a body is moving with a speed of 25 metre per second Express its speed in kilometre per hour

Answer 1

1 km = 1000 m
1 h = 60×60 = 3600 s

1 km/h = (1000m)/(3600s)
= (1000/18) m/s
= 5/18 m/s

So, 1 m/s = 18/5 km/h

So, 25 m/s = 25 × 18/5 km/h
= 5×18 km/h
= 90 km/h


Thus, 25 m/s = 90 km/h

Answer 2

speed = 25m/s

to convert m/s to km/hr we need to multiply by 18/5

25 x 18/5

450/5

=90km/hr
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to convert km/hr to m/s we need to multiply the value by 5/18