Aptitude - Problems on Trains - Discussion
Discussion Forum : Problems on Trains - General Questions (Q.No. 1)
1.
A train running at the speed of 60 km/hr crosses a pole in 9 seconds. What is the length of the train?
Answer: Option
Explanation:
| Speed = |  |
60 x | 5 |  m/sec |
= | |
50 | m/sec. |
| 18 | 3 |
Length of the train = (Speed x Time).
 Length of the train = |
|
50 | x 9 | m = 150 m. |
| 3 |
Discussion:
587 comments Page 5 of 59.
Madhu said:
6 years ago
The train covers its own distance/length in 9 seconds. Therefore, its length is the distance it covers in 9 seconds. Now lets convert the speed into metres and time in seconds. The train covers 60000 metres in 3600 seconds. Therefore in 9 seconds, it would cover;
(60000/3600*9) = 150 metres.
(60000/3600*9) = 150 metres.
Marylyn Kaka said:
9 years ago
Speed = distance(length of train) / Time.
Length of train = speed * time.
First, express 9 seconds in hours since speed is in hours.
9 / 3600 = 0.0025.
Length = speed * time.
= 60 * 0.0025.
= 0.15 km.
Convert 0.15 km to meters since options are in meters.
=0.15 * 1000.
=150 m.
Length of train = speed * time.
First, express 9 seconds in hours since speed is in hours.
9 / 3600 = 0.0025.
Length = speed * time.
= 60 * 0.0025.
= 0.15 km.
Convert 0.15 km to meters since options are in meters.
=0.15 * 1000.
=150 m.
Joseph said:
1 decade ago
First convert the km into metres 60km will bcome 60000 metres then divide 60000 with 1 hour that is 60,60000/60 this will give us the speed of the train in mins n then 1000 with 60(to convert the speed in seconds)then multiply the ans with 9 seconds.ie 16.66*9 will give us 150 :)
Saran said:
1 decade ago
Distance = time*speed.
Distance = 9sec*60(km/hr).
Here the the time is in 'seconds' and answer will given into the 'm', so we will convert all the values into the 'm&sec'.
1km = 1000m.
1hr = 3600sec.
Then,
Distance = 9*60(1000/3600).
Distance = 9*60(5/18).
Distance = 150m.
Distance = 9sec*60(km/hr).
Here the the time is in 'seconds' and answer will given into the 'm', so we will convert all the values into the 'm&sec'.
1km = 1000m.
1hr = 3600sec.
Then,
Distance = 9*60(1000/3600).
Distance = 9*60(5/18).
Distance = 150m.
Pradeep said:
1 decade ago
The answer is simple. We are converting the 'kilo-meters/hour' value into 'meters/second'.
Let me explain about converting km/hr into m/s in detail.
1 km = 1000 meters.
1 hr = 3600 seconds.
1 km/hr = 1000/3600 m/s
= 10/36 m/s
= 5/18 m/s.
Therefore 1 km/hr = 5/18 m/sec.
Let me explain about converting km/hr into m/s in detail.
1 km = 1000 meters.
1 hr = 3600 seconds.
1 km/hr = 1000/3600 m/s
= 10/36 m/s
= 5/18 m/s.
Therefore 1 km/hr = 5/18 m/sec.
Sparsh said:
4 years ago
I thought the timelapse is started when the front portion of the train just comes in contact with the bridge. If that were the case then the total length covered in 30 seconds is the length of the train twice plus the length of the bridge. So, the answer comes to be 115m.
Kenshika venistran said:
3 years ago
We know that 1 kilometre = 1000 meters and 1 hour = 3600 seconds.
Now, 1 km/h can also be written as 1000/3600: 1 (kilometre/hour) = 1000/3600 (meters/seconds).
So, this is the formula which is used to convert km/h to m/s.
On simplifying 1000/3600 further, we get 5/18.
Now, 1 km/h can also be written as 1000/3600: 1 (kilometre/hour) = 1000/3600 (meters/seconds).
So, this is the formula which is used to convert km/h to m/s.
On simplifying 1000/3600 further, we get 5/18.
(73)
Suganthan.m said:
1 decade ago
From the question we can predict speed= distance/hour
((by speed=60 km/hr)note the km/hr)
As to calculate for 9 sec I am converting the whole things to seconds
(i.e.)speed=60000/3600=16.666666(remember this is for one second)
therefore for 9 seconds
16.666666*9= 150
((by speed=60 km/hr)note the km/hr)
As to calculate for 9 sec I am converting the whole things to seconds
(i.e.)speed=60000/3600=16.666666(remember this is for one second)
therefore for 9 seconds
16.666666*9= 150
Roko Meena said:
10 years ago
By using unit logic we can solve this question easily in question (given unit are km, m, sec).
Length of train in meter.
So, 60 km/hr.
= 60*1000 m/1*3600 sec.
1 km = 1000 m and 1 hour = 3600 sec.
= 1000 m*9 sec/3600 sec.
Sec unit cancel so I find (meter) 150 m.
Length of train in meter.
So, 60 km/hr.
= 60*1000 m/1*3600 sec.
1 km = 1000 m and 1 hour = 3600 sec.
= 1000 m*9 sec/3600 sec.
Sec unit cancel so I find (meter) 150 m.
BIJAY said:
4 years ago
@All.
We know that;
Velocity = Distance/Time.
so we can write,
Distance = Velocity*Time.
= (16.66)*(9) meters [=> 60km/hr convert into meters = 60*5/18. = 16.66 meter/sec.].
= 150 meters. [ANS].
We know that;
Velocity = Distance/Time.
so we can write,
Distance = Velocity*Time.
= (16.66)*(9) meters [=> 60km/hr convert into meters = 60*5/18. = 16.66 meter/sec.].
= 150 meters. [ANS].
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