Answer:
The value is [tex]t =29.2 \ s [/tex]
Explanation:
From the question we are told that
Generally the average velocity of the train is mathematically represented as
[tex]v = \frac{u + v}{2}[/tex]
substituting 82.4 km/h for u and 16.4 km/h. for v
[tex]v = \frac{82.4 + 16.4}{2}[/tex]
[tex]v = 49.4 \ km/h[/tex]
Generally the time taken is mathematically represented as
[tex]t = \frac{ L}{v}[/tex]
substituting 49.4 \ km/h for v and [tex]4.00 * 10^2 \ m = 0.400 \ km[/tex]
[tex]t = \frac{ 0.400}{49.4}[/tex]
[tex]t = 0.00809 \ h [/tex]
converting to seconds
[tex]t = 0.00809 * 3600 [/tex]
[tex]t =29.2 \ s [/tex]
