The length of the bridge, which a train 130 m long and travelling at 45 km h- 1 can cross in 30 seconds, is:

Question

The length of the bridge, which a train 130 m long and travelling at 45 km h- 1 can cross in 30 seconds, is: (A) 200m (B) 225 m (C) 245 m (D) 250 m

Tardigrade Admin · Accepted Answer

Speed = (45 × (5/18))ms- 1⇒ ((25/2)) ms- 2 ; Time= 30 s . Let the length of the bridge be x metres. Then, (130 + x/30)=(25/2) Leftrightarrow 2(.130 + x.) = 750 Leftrightarrow x = 245 m

Q. The length of the bridge, which a train $130 m$ long and travelling at $45 km h^{- 1}$ can cross in $30$ seconds, is:

$200 m$

$225 m$

$245 m$

$250 m$

Speed $= (45 \times \frac{5}{18}) m s^{- 1} \Rightarrow (\frac{25}{2}) m s^{- 2}$ ; $T im e = 30 s$ .
Let the length of the bridge be x metres.
Then, $\frac{130 + x}{30} = \frac{25}{2} \Leftrightarrow 2 (130 + x) = 750 \Leftrightarrow x = 245 m$

Q. The length of the bridge, which a train 130m long and travelling at 45kmh−1 can cross in 30 seconds, is:

200m

225m

245m

250m