Problem on
Trains is an another important topic of chapter Time Speed and Distance from
competition point of view. In the previous post of Problem based on trains we
have discussed about some basic concepts of this chapter. Now we will see some more
of the various frequently asked important question of this chapter in
competition like SSC, Bank (IBPS), and Railways.
Important Types questions on Trains:-
Concept 2nd
:- Train crossing stationary pole, Telegraph
post or a stationary man:-
Q4. A train 120 m long, running at a speed of 108 km/hr. In how
much time will crosses an electric pole?
Note :- In this type of questions the only thing to be noticed is
that all the dimensions should be same unit scale means either distance in kilometres and time in hours or
distance in metres and time in seconds.
As we have discussed in the previous post of this topic that in
such questions:-
the
distance travelled by the train = length of the train
Formula used in such questions :-
Speed of train = distance travelled/time
taken to cross
Sol. Given Data :- Speed of train = 108 kilometers/hours. = 108 ×
(5/18) m/sec
= 30 m/sec.
and length of train = distance travelled by the train = 120 metres.
Let taken by the train to cross the electric pole = t sec.
Now, speed of the train = Distance/time
30 = 120/t
On simplifying we get:- t =
120/30
= 4 sec.
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Hence
the required time taken by the train to cross the electric pole is 4sec.
Concept 3rd :- Trains crossing a
platform/ bridge/ tunnel or stationary with length.
Q5. A train, 250 meters long running with a speed of 72 km/hr. In
what time will it pass a platform with a length of 110 meters.
Note :- In this type of questions the only thing to be noticed
is that all the dimensions should be same unit scale means either distance in kilometres and time in hours
or distance in metres and time in seconds.
As we have discussed in the previous post of this topic that in
such questions:-
the
distance travelled by the train = length of the train + length of platform/
tunnel/ bridge
Formula used in such questions :-
Speed of train = distance travelled/time
taken to cross
Sol. Given Data :- Speed
of train = 72 kilometers/hours. = 72 × (5/18) m/sec
= 20 m/sec.
Length of platform = 110 meters
Therefore distance travelled by the train = length of train +
length of platform
= 250 + 110 = 360 metres.
Let taken by the train to cross the electric pole = t sec.
Now, speed of the train = Distance/time
20 = 360/t
On simplifying we get:- t
= 360/20
=
18 sec.
Hence
the required time taken by the train to cross the platform is 18 seconds.
Q6. A train, 285 meters long is running at a speed of 126
kms/hr. In how much time will it cross a tunnel, which is 415 meters long?
Sol. Given Data :- Speed
of train = 126 kilometers/hours. = 126 × (5/18) m/sec
= 35 m/sec.
Length of tunnel = 415 meters
Therefore distance travelled by the train = length of train +
length of tunnel
= 285 + 415 = 700 metres.
Let taken by the train to cross the tunnel = t sec.
Now, speed of the train = Distance/time
35 = 700/t
On simplifying we get:- t
= 700/35
=
20 sec.
Hence
the required time taken by the train to cross the platform is 20 seconds.
(Note you may say that this is so
long but dear this is the only way to explain the whole concept of the
question to you now its upto you that how fast and short handedly you can
solve these type of questions)
Hope
you have enjoyed the base concept of this chapter till now. More Conceptual
enjoyment with the Various Questions related to this chapter which are
frequently asked in the examinations will be presented to your for self study
on this blog soon, just keep visiting this blog regularly and writing me your
related queries through comment or forum.
More
types of questions will be followed soon on this blog........................
Best of
Luck for Exams. To be continued soon........................
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