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:
636 comments Page 4 of 64.
Dhanu said:
5 months ago
The speed of the train = 60km/hr.
Pole cross time = 9 sec
So, convert speed into secs 1hr =60 minutes per minute 60 sec.
to convert 1hr in sec = 60 * 60 = 3600sec.
Now, convert km into meters 1km = 1000m.
then, speed = (60 * 1000/3600) m/s.
= (60 * 5/18) = 16.67m/s.
Now, the length of the train = speed * time.
= 16.67 * 9 = 150m.
Pole cross time = 9 sec
So, convert speed into secs 1hr =60 minutes per minute 60 sec.
to convert 1hr in sec = 60 * 60 = 3600sec.
Now, convert km into meters 1km = 1000m.
then, speed = (60 * 1000/3600) m/s.
= (60 * 5/18) = 16.67m/s.
Now, the length of the train = speed * time.
= 16.67 * 9 = 150m.
(86)
Madhusudan Jena said:
1 year ago
Given Time = 9 sec,
Covert Speed km/hr to m/sec.
1 km = 1000m,
1 hr = 60 min,
1 min = 60 sec.
60 min=(60 * 60) sec = 3600 sec.
So, 1 hr = 3600 sec.
1 hr = 3600 sec.
1 km/hr = 1km/1hr = 1000 m/3600 sec = 10/36 m/s = 5/18 m/s,
Speed = 60 km/hr = 60 * 5/18 m/s,
Speed = Distance/Time.
So, the Length of the train = Speed * Time
= 60 * 5/18*9
= 150m.
Covert Speed km/hr to m/sec.
1 km = 1000m,
1 hr = 60 min,
1 min = 60 sec.
60 min=(60 * 60) sec = 3600 sec.
So, 1 hr = 3600 sec.
1 hr = 3600 sec.
1 km/hr = 1km/1hr = 1000 m/3600 sec = 10/36 m/s = 5/18 m/s,
Speed = 60 km/hr = 60 * 5/18 m/s,
Speed = Distance/Time.
So, the Length of the train = Speed * Time
= 60 * 5/18*9
= 150m.
(70)
Raj said:
8 years ago
They are given speed in terms of km/hr,
Hence we have to convert that unit into m/hr because of all the 4 options are in terms of *meter and they are asking us the length in * 9 seconds.
After we convert in terms of m/s, then just we have to multiply the value we have converted (m/s) with 9 seconds.
I hope you will understand.
Hence we have to convert that unit into m/hr because of all the 4 options are in terms of *meter and they are asking us the length in * 9 seconds.
After we convert in terms of m/s, then just we have to multiply the value we have converted (m/s) with 9 seconds.
I hope you will understand.
Naveen said:
1 year ago
Kilometers to meters: There are 1000 meters in 1 kilometer.
Hours to seconds: There are 60 minutes in 1 hour, and 60 seconds in 1 minute, so there are 60×60=3600 seconds in 1 hour.
So, to convert a speed from km/hr to m/sec, you multiply by 3600 seconds1000 meters.
Now, let's simplify that fraction:
36001000 = 3610 = 185.
Hours to seconds: There are 60 minutes in 1 hour, and 60 seconds in 1 minute, so there are 60×60=3600 seconds in 1 hour.
So, to convert a speed from km/hr to m/sec, you multiply by 3600 seconds1000 meters.
Now, let's simplify that fraction:
36001000 = 3610 = 185.
(10)
Nisar Ahmed said:
3 years ago
60 Km/hr.
1 km = 1000 m
1 hr = 60 min.
1 min = 60 sec.
Converting km/hr into m/sec.
1000m / 3600sec = 5/18,
So, we got this 5/18, Got it.
Now, Just multiply this by the actual value,
(Distance = Speed × Time),
that is; 60 * 5/18 = 50/3 m/sec and this distance is for one sec.
For 9 sec,
multiply 50/3 by 9.
50/3 * 9 = 150m.
1 km = 1000 m
1 hr = 60 min.
1 min = 60 sec.
Converting km/hr into m/sec.
1000m / 3600sec = 5/18,
So, we got this 5/18, Got it.
Now, Just multiply this by the actual value,
(Distance = Speed × Time),
that is; 60 * 5/18 = 50/3 m/sec and this distance is for one sec.
For 9 sec,
multiply 50/3 by 9.
50/3 * 9 = 150m.
(54)
Sikkanthar said:
1 decade ago
Here they are converting the unit of speed from kmph into m/s.
So they are taking the equal value of each one like.
Km = 1000m.
1 hour = 3600s.
So they are using the value of 5/18 here.
They what formula they were used to solve this problem means.
Length/time = speed.
So we can calculate unknown with help of given data.
So they are taking the equal value of each one like.
Km = 1000m.
1 hour = 3600s.
So they are using the value of 5/18 here.
They what formula they were used to solve this problem means.
Length/time = speed.
So we can calculate unknown with help of given data.
Nagaraju said:
2 decades ago
Here we have to think that they are asking the length of train.
First we have conform that all the values given are same format or not .
if not we have to convert them into one format depending on the answers given to us.
Then it is possible to get the correct answer.
The first answer explanation by Sundar is very good .
First we have conform that all the values given are same format or not .
if not we have to convert them into one format depending on the answers given to us.
Then it is possible to get the correct answer.
The first answer explanation by Sundar is very good .
Aathilakshmi said:
3 years ago
Length of the train = Speed × Time.
Time=9s.
Speed = 60 km/hr. (To convert speed into m/s from km/hr)
1km = 1000m so 60km = 60000m.
1 hr = 3600seconds.
Speed = 60000/3600 m/s.
= 50/3 m/s.
Length of the train = Speed × time.
= 50/3×9.
= 150m.
Time=9s.
Speed = 60 km/hr. (To convert speed into m/s from km/hr)
1km = 1000m so 60km = 60000m.
1 hr = 3600seconds.
Speed = 60000/3600 m/s.
= 50/3 m/s.
Length of the train = Speed × time.
= 50/3×9.
= 150m.
(78)
Muhammad Abdurrehman said:
1 decade ago
Solution:
All Quantities are given in question.
Note: Answer is in the meter so will convert km/hr to m/s.
Given Data:
1. Speed = 60km/hr = 60*(1000/3600) = 100/6 m/s = 16.666m/s.
2. Time = 9 sec.
Sol: We know that speed = distance/ time.
Speed(s) = v/t or v = s * t = 16.666m/sec*9 sec.
So, s = 150 meters.
All Quantities are given in question.
Note: Answer is in the meter so will convert km/hr to m/s.
Given Data:
1. Speed = 60km/hr = 60*(1000/3600) = 100/6 m/s = 16.666m/s.
2. Time = 9 sec.
Sol: We know that speed = distance/ time.
Speed(s) = v/t or v = s * t = 16.666m/sec*9 sec.
So, s = 150 meters.
Madhira kusuma said:
3 years ago
See here :
1km=1000meters
1 hr=3600 sec.
By dividing both meters and seconds here we get =1000/3600.
At final we get 5/18.
Length = (speed×time).
L=(60×5/18).
So here we get = 50/3.
Then finally calculate the total length of the train = (50/3 × 9).
M = 150.
Thank you
1km=1000meters
1 hr=3600 sec.
By dividing both meters and seconds here we get =1000/3600.
At final we get 5/18.
Length = (speed×time).
L=(60×5/18).
So here we get = 50/3.
Then finally calculate the total length of the train = (50/3 × 9).
M = 150.
Thank you
(569)
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