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:
619 comments Page 3 of 62.
Vagdevi said:
7 years ago
Speed=distance/time -> Distance=speed * time.
As time in seconds, we have to change the speed to m/sec from km/hr.
For doing so we have to multiply the speed with 5/18 (km/hr=1000m/3600 sec=5/18).
Then the distance travel by train is 60*9*5/18=150m.
Because of the train crosses the pole, The distance travelled by the train equal to the length of the train.
Therefore the length of the train is 150 m.
As time in seconds, we have to change the speed to m/sec from km/hr.
For doing so we have to multiply the speed with 5/18 (km/hr=1000m/3600 sec=5/18).
Then the distance travel by train is 60*9*5/18=150m.
Because of the train crosses the pole, The distance travelled by the train equal to the length of the train.
Therefore the length of the train is 150 m.
Mhs said:
2 years ago
The train is running at 60 km per hour and it crosses the poll in 9 seconds to calculate the length of the train the formula is length = speed * time
let's calculate;
60 km = 60000 m.
60 min = 60 * 60 = 3600 sec,
let's calculate speed per second:
60000/ 3600 = 16.666666 = 16.666666 m/s.
In one second train covered the 16.666666 m.
so the train crossed the poll in 9 second.
so;
16.666666 * 9 = 150.
let's calculate;
60 km = 60000 m.
60 min = 60 * 60 = 3600 sec,
let's calculate speed per second:
60000/ 3600 = 16.666666 = 16.666666 m/s.
In one second train covered the 16.666666 m.
so the train crossed the poll in 9 second.
so;
16.666666 * 9 = 150.
(196)
Vigneshwaran said:
8 months ago
We are given speed as 60 km/h.
But we need the answer in meters per second (m/s).
1. First, we convert kilometres to metres:
1 km = 1000 meters.
So 60 km = 60 × 1000 = 60,000 meters.
2. Next, convert hours to seconds:
1 hour = 60 minutes
= 60 × 60 = 3600 seconds.
3. Now divide the distance by time:
60,000 ÷ 3600 = 16.666… ≈ 16.67 m/s.
then 16.6 x 9 = 150.
Then the final answer is 150 meters.
But we need the answer in meters per second (m/s).
1. First, we convert kilometres to metres:
1 km = 1000 meters.
So 60 km = 60 × 1000 = 60,000 meters.
2. Next, convert hours to seconds:
1 hour = 60 minutes
= 60 × 60 = 3600 seconds.
3. Now divide the distance by time:
60,000 ÷ 3600 = 16.666… ≈ 16.67 m/s.
then 16.6 x 9 = 150.
Then the final answer is 150 meters.
(164)
Vikram said:
1 decade ago
Here,The Train speed =60km/1hr & That Train was crosses a one Pole in 9 Seconds.
So,Therefore we are converting Km into Meters And Hour into Seconds.....
i.e.,That train speed=60km/60Minute.
i.e.,that Train Speed=1km/1Minute.
and 1km=1000meters ,1Minute=60seconds.
So,The Train Length = 1Km/1Minute *9.
that means ,Length of Train=(1000/60)*9.
=150 Meters.
So,Therefore we are converting Km into Meters And Hour into Seconds.....
i.e.,That train speed=60km/60Minute.
i.e.,that Train Speed=1km/1Minute.
and 1km=1000meters ,1Minute=60seconds.
So,The Train Length = 1Km/1Minute *9.
that means ,Length of Train=(1000/60)*9.
=150 Meters.
ANIL said:
1 decade ago
@Bangaru.
If the total salary is 100%, in which 15% spent on insurance policy means 100-15 =85%.
55% spent as expenditure on shopping etc means 85-55 =30%
Savings =salary -expenditure.
30% savings equals to 12,750.
Percentage can be represented as per hundred i.e., 30/100, which is equals to 12,750.
Assume that total salary be X
X *30/100 =12,750
X =12750*100/30
X= 42500.
If the total salary is 100%, in which 15% spent on insurance policy means 100-15 =85%.
55% spent as expenditure on shopping etc means 85-55 =30%
Savings =salary -expenditure.
30% savings equals to 12,750.
Percentage can be represented as per hundred i.e., 30/100, which is equals to 12,750.
Assume that total salary be X
X *30/100 =12,750
X =12750*100/30
X= 42500.
Henry Pautu said:
1 year ago
To find the length of the train, we use the formula is Distance=Speed×Time.
Given:
Speed of the train = 60 km/hr.
Time taken to cross the pole = 9 seconds.
Since 1 km/hr = (5/18) m/s, we convert:
60 X 5 / 18 = 300 / 18 = 16.67 m/s.
Since the train crosses a pole (which means the length of the train itself is covered in the given time):
Length of train = 16.67 × 9 = 150 meters.
Given:
Speed of the train = 60 km/hr.
Time taken to cross the pole = 9 seconds.
Since 1 km/hr = (5/18) m/s, we convert:
60 X 5 / 18 = 300 / 18 = 16.67 m/s.
Since the train crosses a pole (which means the length of the train itself is covered in the given time):
Length of train = 16.67 × 9 = 150 meters.
(13)
Ranjeet_Great said:
1 decade ago
@Udai.
Its very easy to convert m/sec in to km/hour,
Just multiply 18/5.
For example if we want to convert 5meter/sec in to km/sec then we will convert meter into km and sec in to hour.
That is 5meter=(5/1000)km and 1sec=(1/3600)hour.
So 5m/sec={(5/1000)/(1/3600)} km/hour.
or (5*3600)/(1*1000) km/hour
or (5*36)/(10) km /hour
or (5*18)/(5) km/hour
or 5 km/hour.
Its very easy to convert m/sec in to km/hour,
Just multiply 18/5.
For example if we want to convert 5meter/sec in to km/sec then we will convert meter into km and sec in to hour.
That is 5meter=(5/1000)km and 1sec=(1/3600)hour.
So 5m/sec={(5/1000)/(1/3600)} km/hour.
or (5*3600)/(1*1000) km/hour
or (5*36)/(10) km /hour
or (5*18)/(5) km/hour
or 5 km/hour.
Shreya shital Upadhye said:
1 year ago
@All.
Here's my explanation.
A train running at a speed of 60 km/h takes 9 seconds to cross an electric pole.
Formula used:
Distance = speed × time.
1 km/h = (5/18) m/sec.
Calculation:
Length of train = distance.
Speed convert km.hr to m/sec.
⇒ 60 × (5/18).
⇒ Speed = 16.67 m/sec.
Distance = 16.67 × 9
⇒ 150 m.
∴ The length of the train is 150 m.
Here's my explanation.
A train running at a speed of 60 km/h takes 9 seconds to cross an electric pole.
Formula used:
Distance = speed × time.
1 km/h = (5/18) m/sec.
Calculation:
Length of train = distance.
Speed convert km.hr to m/sec.
⇒ 60 × (5/18).
⇒ Speed = 16.67 m/sec.
Distance = 16.67 × 9
⇒ 150 m.
∴ The length of the train is 150 m.
(46)
Dhanu said:
3 weeks 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.
(25)
Madhusudan Jena said:
10 months 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)
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