A train running at the speed of 80 km/h crosses a 350 m long tunnel in 36 seconds. The length of the train (in m) is
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → 450
To cross a tunnel, a train must cover its own length plus the length of the tunnel: the engine enters at one end and the last coach must leave the other end.
Speed \(\displaystyle =80\times\frac{5}{18}=\frac{200}{9}\,\mathrm{m/s}\) (1 km/h \(=\frac{5}{18}\) m/s)
Distance covered in 36 s \(\displaystyle =\frac{200}{9}\times36=800\,\mathrm{m}\)
Length of the train \(=800-350=450\,\mathrm{m}\)