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:
592 comments Page 3 of 60.
Mhs said:
1 year 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.
(195)
Vigneshwaran said:
2 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.
(156)
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:
8 months 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:
10 months 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)
Madhusudan Jena said:
4 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)
Raj said:
7 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:
5 months 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)
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