Question 536647
Train speed = 100 kph
Motorcycle speed = 40 kph

They are moving in same direction
so effective speed = 100-40 = 60 kph

Time = 48 seconds
=48/3600 hours (1 hour = 3600 seconds)

d=speed * time
D= 60*48/3600
=0.8 km or 800 meters

Towards each other
Add up speeds
effective speed = 140 kph
The length of train is the distance they have to travel to pass one another
distance = 0.8 km
time = distance / speed
time = 0.8/140
time=0.0057 hours
convert to seconds
0.0057*3600
= 20.57 seconds

m.ananth@hotmail.ca