In this article, we will get to know how to deal with train problems.

Basic Concepts

So let first see the basic concept:

Distance: When an object simply moves from one place to another. We measure it in Km or m.
Time: It represents how much time an object needs to cover a particular distance. We measure it in hr or s.
Speed: It simply represents at what pace an object is moving. We measure it in km/hr or m/s.

These three things relate to each other and give us a formula which is:

Speed = Distance/Time

v=s/t

Types of Questions Normally Asked from Train Problem 

• Asking Questions where conversion is needed

  • Converting Km/h to m/s =meter/ (minute * seconds) =    1000/(60*60) = 5/18 m/s
  • Converting m/s to Km/h = (minute * seconds) / meter = (60*60)/ 1000 = 18/5 Km/h

Q. A train moves with a speed of 10 km/h. What distance it will cover in 20 s?

First, convert the speed in m/s = 10 *5 /18  = 50/18 m/s

Now find the distance =  d = s * t

d = (50/18)* 20 = 55.5 m

• Asking Direct Question where two parameters are given and required to find the third one by simply using the distance formula

  • Use,  Speed = Distance/time

Q. A train moves with a speed of 10 km/h. Find its distance after traveling for 2 hours?

Speed =10km/h

Distance= ?

Time = 2 hrs

10km/h = ?/2 hrs

distance = 10km/h *2 hrs

distance = 20km

• Asking a question about a moving object relative to a stationary object such as  a person, bridge, platform, and more

  • If a stationary object is a poll, person or a tree and to know when a moving object would completely cross that  stationary object= length of object/ speed
  • If a stationary object is a bridge, platform and to know when a moving object would completely cross that stationary object= length of object + length of platform or bridge/ speed

Q. A train is 600 m long and moving with a speed of 200 m/s. What time does it cross 600 m long Platform?

Speed = 200 m/s

Distance = ( length of train + length of platform) / t

t = (600m + 600m )/200 m/s

t = 1200m/200 ms

=6 s

• Asking Train Problem Questions based on Relativity Theory

  • If two moving vehicle is moving in the same direction and to know at what time they cross each other
    • Time = (length of first moving object + length of a second moving object)/ (Speed of the first train – Speed of the second train)
  • If two moving vehicle are moving in opposite directions and to know at what time they cross each other
    • Time = (length of first moving object + length of a second moving object)/ (Speed of the first train + Speed of the second train)

Q. Train A 200 m long moves with a speed of 150 m/s and Train B 300 m long moves with a speed of 150 m/s. If both trains are opposite to each other, at what time they cross each other.

Distance = length of train A + length of train B = 200 + 300 = 500 m

Speed =  speed of train A + speed of train B = 150 + 150 = 300 m/s

t = 500/300 = 5/3 s