Aptitude - Problems on Trains - Discussion
Discussion Forum : Problems on Trains - General Questions (Q.No. 10)
10.
A jogger running at 9 kmph alongside a railway track in 240 metres ahead of the engine of a 120 metres long train running at 45 kmph in the same direction. In how much time will the train pass the jogger?
Answer: Option
Explanation:
Speed of train relative to jogger = (45 - 9) km/hr = 36 km/hr.
| = |  |
36 x | 5 |  m/sec |
| 18 |
= 10 m/sec.
Distance to be covered = (240 + 120) m = 360 m.
 Time taken = |
|
360 | sec |
= 36 sec. |
| 10 |
Discussion:
106 comments Page 10 of 11.
Pratik said:
7 years ago
@All.
I have a doubt. The jogger was not static. This means he/she must have covered some distance before the train crosses, all the solutions have not included this issue. Should I neglect that distance or is there anything I am missing.
To me, total distance = train length+ 240 metre+ the joggers covered path.
Is that correct or not. If not please help.
I have a doubt. The jogger was not static. This means he/she must have covered some distance before the train crosses, all the solutions have not included this issue. Should I neglect that distance or is there anything I am missing.
To me, total distance = train length+ 240 metre+ the joggers covered path.
Is that correct or not. If not please help.
Shubhangi nema said:
7 years ago
A jogger is a point object so why we consider the platform length?
Vivek Manve said:
7 years ago
Jogger is also running. So he will cover some distance, that should be taken in calculation right?
Jime said:
7 years ago
Why do we add the distance with direction?
MasterMind said:
7 years ago
Same direction,
d1+d2=240+120,
d=360,
speed :(same direction,)
s1-s2=45-9=36kmph.
36*5/18=10m/s,
therefore,
assume time=x,
d=speed*time ,
360=10*(x).
36 = x.
d1+d2=240+120,
d=360,
speed :(same direction,)
s1-s2=45-9=36kmph.
36*5/18=10m/s,
therefore,
assume time=x,
d=speed*time ,
360=10*(x).
36 = x.
Kavya said:
7 years ago
Why didn't we use relative speed formula here instead why we did use the speed of train relative to jogger?
Please explain me.
Please explain me.
Karthik said:
7 years ago
Why relative speed covered entire distance. I suspect that when train engine enter to jogger after that we should consider relative speed?
Please explain anyone.
Please explain anyone.
Rohan said:
6 years ago
Why is the total distance taken as 240+120?
Arpan Manchanda said:
6 years ago
@All.
Please let me know why we have considered the complete length of the track, may be jogger is in half of the way or but the question here is train is crossing jogger, they are running in the same direction hence we have considered relative velocity but when the train is passing a jogger, jogger don't have any length. Please elaborate.
Please let me know why we have considered the complete length of the track, may be jogger is in half of the way or but the question here is train is crossing jogger, they are running in the same direction hence we have considered relative velocity but when the train is passing a jogger, jogger don't have any length. Please elaborate.
Abhishek said:
6 years ago
The jogger is ahead of the train by 240m and the question asks us to find the time train takes to pass the jogger, should we consider the time taken to cover distance of 240m and then add time take to cross the jogger.
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