Suppose u walk across the room of length 9 m with the velocity of 1.5m perhr. Calculate the velocity in m/s and the time taken to move across the room

1.5 m/hr * 1hr/3600s = 1/2400 m/s

now, recall that

time = distance/speed

and use that

what are you, a slug?

Maybe you meant 1.5 km/hr. If so, jack up the speed by a factor of 1000.