Answer:

(i) 1 km per hour =

60×60

100m

metres per second =

18

5

m/s ∴315km/h=315×

18

5

m/s=

2

175

m/s=87.5m/s

76 km/h into ms:-

1 KM=1000m

so , 76KM=76*1000m

               =76000m

1 hr=60 minutes

1 minute=60 seconds

so , 1 hr=60*60s

           =3600s

now, 76KM/h=7600/3600

                     =21.11 m/s ANSWER