A train 700 m long is running at 72 kmph. If it crosses a tunnel in 1…

Speed in m/s = 72 x \(\frac{ 5}{ 18}\) m/s

Speed in m/s = 20 m/s

Let the length of the tunnel be x

20 = \(\frac{\text{700 + x}}{ 60}\)

1200 = 700 + x

x = 500 m