Question

A train 450 m long is running at a speed of 45km/hr.

What time will it take to cross a 175 m long bridge?

want full explanation ​

Answer 1

Answer:

50 seconds

Step-by-step explanation:

Length of train = 450 m

Length of bridge = 175 m

Total distance = (450+175) m = 625 m

Speed of train = 45 km/h = (45 × 5/18) m/s = 12.5 m/s

Time taken = Distance/Speed = (625/12.5) seconds = 50 seconds

Answer 2

Given:

A train 450 m long is running at a speed of 45km/hr.

To Find:

What time train will take to cross a 175-meter long bridge?

Step-by-step explanation:

• In the given question a 450 m long train is running at a speed of 45 km/hr.

       We know that Time is the ratio of Distance covered to speed.

                                       $Time=\frac{Total distance }{speed}$

• Distance covered by train to cross bridge = train length + bridge length.

                                             $\textrm{Total distance}=(450+175)m\\\textrm{Total distance}=625m$

                                              $\textrm{Speed of train}= 45km/h$

       $\textrm{To convert speed of the train to m/s we will multiply by}$  $\frac{5}{18}$   .

                                                $\textrm{Speed of train}= 45\times \frac{5}{18}$

                                                                        $=12.5 m/s$

• Put values of speed and total distance in the formula.

                                               $Time=\frac{625}{12.5}$

                                             $Time =50s$

So, train will take 50 seconds to cross a 175m long bridge.