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 5 of 64.
Aaftab ali said:
3 years ago
Speed = 60 km/hr
Time = 9
Length = ?
Length = speed * time.
The first step convert km/hr into m/s
Formula is [ km/hr * 5/18 ] = m/s.
So,
60 km/hr * 5/18 = 50/3 m/s.
Now you have speed in metre so find the length now......
Speed * time = length.
50/3 * 9 = ? (Length).
150 = length.
So, the answer is 150 m.
Time = 9
Length = ?
Length = speed * time.
The first step convert km/hr into m/s
Formula is [ km/hr * 5/18 ] = m/s.
So,
60 km/hr * 5/18 = 50/3 m/s.
Now you have speed in metre so find the length now......
Speed * time = length.
50/3 * 9 = ? (Length).
150 = length.
So, the answer is 150 m.
(36)
Ruchita said:
1 year ago
Firstly, you need to check what's given in the question.
So, Now.
THe Time given in seconds.
Distance needed in meters.
So, convert km/hr to m/sec.
1km = 1000m
1hr = 3600sec.
1km/hr = 1000/3600 = 5/18(m/sec).
speed = (60 *5/18) = 50 /3(m/sec).
At last,
The Length = Speed * Time = (50/3 * 9) = 150meters.
So, Now.
THe Time given in seconds.
Distance needed in meters.
So, convert km/hr to m/sec.
1km = 1000m
1hr = 3600sec.
1km/hr = 1000/3600 = 5/18(m/sec).
speed = (60 *5/18) = 50 /3(m/sec).
At last,
The Length = Speed * Time = (50/3 * 9) = 150meters.
(153)
Venkat Reddy said:
1 decade ago
Good @Sai Mohan Reddy.
We can also show like this; for 3 sec_____50 mtr, then 9 sec____? mtr;
50*9/3 = 450/3 or (50*3) = 150 mtr length of the train.
(It is a time saving problem, calculation should take place in seconds. 60 kmph means 60000/3600 (m/sec) = 50 mtr in 3 sec. Then calculate for 9 sec).
We can also show like this; for 3 sec_____50 mtr, then 9 sec____? mtr;
50*9/3 = 450/3 or (50*3) = 150 mtr length of the train.
(It is a time saving problem, calculation should take place in seconds. 60 kmph means 60000/3600 (m/sec) = 50 mtr in 3 sec. Then calculate for 9 sec).
Moupiya said:
1 decade ago
Train Cross Stationary object without length.
t = Lt/St.
Lt = length of train.
St = speed of train.
Can I follow this formula for this question as I follow made easy book and for this type of question this formula is used but I'm not getting the answer thru this formula.
Can any 1 help.
Thankyou.
t = Lt/St.
Lt = length of train.
St = speed of train.
Can I follow this formula for this question as I follow made easy book and for this type of question this formula is used but I'm not getting the answer thru this formula.
Can any 1 help.
Thankyou.
TALADA SANDEEP said:
1 decade ago
Since time is given in seconds , sure you have to convert velocity of train in units of m/sec
Since 1 km = 1000 m
and 1 hr =60 m = 60*60 sec,
According to question,speed 60 km/hr = 60 * (1000/3600) = 50/3 m/sec, time = 9 sec
We know that , distance=speed*time,
therefore length = (50/3)*9 =150 m.
Since 1 km = 1000 m
and 1 hr =60 m = 60*60 sec,
According to question,speed 60 km/hr = 60 * (1000/3600) = 50/3 m/sec, time = 9 sec
We know that , distance=speed*time,
therefore length = (50/3)*9 =150 m.
Madhu said:
7 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:
1 decade 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:
2 decades 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.
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