Two trains are moving at 450 miles apart are traveling in the same direction at speeds of 50m/h and 80m/h. a. When will they met? b. How far will the second train travel during this time period

Two trains 130 m and 140 m long are running on parallel tracks in the same direction with a speed of 68 km/hr and 50 km/hr. How long will it take to clear off each other from the moment they meet?

Solution:            

Relative speed of trains = (68 – 50) km/hr

                               = 18 km/hr

                               = 18 × 5/18 m/sec

                               = 5 m/sec

Time taken by the train to clear off each other = sum of length of trains/relative speed of trains

                                                               = (130 + 140)/5 sec

                                                               = 270/5 sec

                                                               = 54 sec

2. The two trains are running on parallel tracks in the same direction at 70 km/hr and 50 km/hr respectively. The faster train passes a man 27 second faster than the slower train. Find the length of the faster train.

Relative speed of the trains = (70 – 50) km/hr

                                     = 20 km/hr

                                     = 20 × 5/18 m/sec

                                     = 50/9 m/sec

Length of the faster train = relative speed × time taken by train to pass

                                     = 50/9 × 27 m

`                                    

i'm thinking more like energy

the answer is a 3.8cm

explanation: