Passenger train passing power pole

A passenger train of length L = 100 m travels at a speed of v = 72 km/h. How long does it take the train to pass a power pole?
How to solve this physics task?

First of all, make sure that all the assigned quantities are in the si base units. How we can see, we must convert speed from km/h to m/s. [tex]v = 72 km/h = 20 m/s[/tex]

To find passing time, we will use that formula: [tex]t=\frac{L}{v}[/tex]. So complete solution is [tex]t=\frac{100m}{20m/s}=5s[/tex].

Answer: the train passes the power pole in 5s.