Question

1. Two trains 115 m and 135 m long are running along parallel tracks at the speeds of
35 km/h and 45 km/h respectively. How long will they take to pass by each other if they run
(i) in opposite directions (ii) in the same direction?
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Answer 1

Answer:

Step-by-step explanation:

In Same direction

total length of train=115+135=250m

Relative speed=45-35=10km/h

In meter per second=10x5/18=25/9

Time taken = 250/25/9=250x9/25=10x9=90 sec

90 sec in min =1min30sec

In opposite directions

Length of train=250m

Relative speed=45+35=80 km/h

In m/s=80x5/18=200/9 m/s

Time taken= 250/200/9=250x9/200= 7.5sec

Answer 2

Answer:

see explanation

Step-by-step explanation:

1st train covers the distance= 115m

2nd train covers the distance=135m

Total distance=115+135=250km

Speed of 1st train =35km/hr=35*18/5

Speed of 2nd train = 45 km/hr

(I) moving in same direction=45-35=10 km/hr

(ii) moving in the opposite direction= 45+35=70 km/hr

(I) Time taken in same direction=