Question

two trains 350m and 250m long are gping at 42km per hour and 30 km per hour respectively in opposite direction. how long would it take them to pass each other

Answer 1

Answer:

30sec

Step-by-step explanation:

Let time taken = t hr

Distance covered by both trains = 42t + 30t = 72t

72t = (350+250)/1000

t = 6/720

t = 1/120 hr

t = 60/120 minutes = 1/2 minute

t = 60/2 = 30 secs

Answer 2

Answer:

Step-by-step explanation:

Distance = (350+250)m = 600 m

Relative speed =(42+30)km/hr

=72km/hr

=(72×1000)60×60m/s

=20 m/s

Time = distance/speed

=600/20 s

=30 s