Question

12. A train 150 metres long running at a speed of 60 km per hour takes 30 seconds to cross a bridge. What is
the length of the bridge?
(A) 250 m​

Answer 1

Answer:

Answer in explanation. Please mark me as brainliast. Hope it helps.

Step-by-step explanation:

Say the length of the bridge is "x" m

In 60 minutes (3600 seconds) the train covers 60 km (60 000 m)

Thus in 30 seconds the train covers (30/3600) x 60 000 = 500 m

This 500 m includes the length of the train, because "crossing" the bridge means the time from the train moving onto the bridge until its last component leaves the bridge.

Thus 500 m = 150 + "x", or "x" = 350 m. Please mark me as brainliast. Hope it helps.