Which of the following speeds is maximum?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 28.4 km/h
Speeds can be compared only in the same unit; here all four are changed to km/h. Since 1 m/s = 3.6 km/h:
7.3 m/s \(=7.3\times3.6=26.28\) km/h
28.4 km/h
6.5 m/min \(=6.5\times60=390\) m/h \(=0.39\) km/h
0.0073 km/s \(=7.3\) m/s \(=26.28\) km/h
The greatest is 28.4 km/h.
Tip: To change m/s to km/h, multiply by \(\displaystyle\frac{18}{5}\); to change km/h to m/s, multiply by \(\displaystyle\frac{5}{18}\).