Which of the following speeds is maximum?

7.3 m/s,

28.4 km/hr = 28.4 (1000/360) = 28.4 (25/9) = (710/9) m/s

6.5m/min = 6.5/60 = (65/600) m/s

0.0073 km/s = 0.0073(1000) = 7.3 m/s

Thus (710/9) m/s that is 28 km/hr is maximum

The correct answer is Option (2) → 28.4 km/h