Question

A train 50 m long passes over a bridge at a constant velocity of 30 km/h. If it takes 36 s to cross the bridge, the length of the bridge will be

• A. 100 m
• B. 200 m
• C. 250 m
• D. 300 m

Answer 1

The correct option is C 250 m

velocity of train in SI unit $\frac{30\times 1000}{3600}$ m/s.

so total distance to be covered is the length of train and length of the bridge (because when a train enters the bridge its front face is at starting point of the bridge and when the train left the bridge then the rear part of train coincide the edge of the bridge.

so $50+S=\frac{300}{36}\times 36$ $=>S=250$.