## Speed, Time and Distance

#### Speed, Time and Distance

1. A train 180 metres long is running at a speed of 90 km/h. How long will it take to pass a post ?
1. 8.2 secs
2. 7.8 secs
3. 8 secs
4. 7.2 secs

1. Speed of train = 90 kmph

 = 90 × 5 m/sec. 18

= 25 m/sec.
When a train crosses a post, it covers a distance equal to its own length.
 ∴  Required time = Distance Speed

 = 180 = 7.2 seconds 25

##### Correct Option: D

Speed of train = 90 kmph

 = 90 × 5 m/sec. 18

= 25 m/sec.
When a train crosses a post, it covers a distance equal to its own length.
 ∴  Required time = Distance Speed

 = 180 = 7.2 seconds 25

1. A train 300 m long is running with a speed of 54 km/hr. In what time will it cross a telephone pole?
1. 20 seconds
2. 15 seconds
3. 17 seconds
4. 18 seconds

1. Speed of train = 54 kmph

 = 54 × 5 m/sec = 15 m/sec 18

 Required time = Length of trains Speed of train

 = 300 = 20 seconds 15

##### Correct Option: A

Speed of train = 54 kmph

 = 54 × 5 m/sec = 15 m/sec 18

 Required time = Length of trains Speed of train

 = 300 = 20 seconds 15

1. A train, 120 m long, takes 6 seconds to pass a telegraph post; the speed of train is
1. 72 km/hr
2. 62 km/hr
3. 55 km/hr
4. 85 km/hr

1.  Speed of train = Length of train Time taken in crossing the pole

 = 120 = 20 m/sec 6

 = 20 × 18 = 72 kmph 5

##### Correct Option: A

 Speed of train = Length of train Time taken in crossing the pole

 = 120 = 20 m/sec 6

 = 20 × 18 = 72 kmph 5

1. A train 100 metres long meets a man going in opposite direction at 5 km/hr and
 passes him in 7 1 seconds. 5
What is the speed of the train (in km/hr) ?
1. 45 km/hr
2. 60 km/hr
3. 55 km/hr
4. 50 km/hr

1. Let speed of train be x kmph
Relative speed = (x + 5) kmph

 Length of train = 100 km 1000

 = 1 km 10

 1 ∴ 10 x + 5

 = 36 5 × 60 × 60

 ⇒ 1 = 1 10(x +5) 500

⇒  x + 5 = 50
⇒  x = 45 kmph

##### Correct Option: A

Let speed of train be x kmph
Relative speed = (x + 5) kmph

 Length of train = 100 km 1000

 = 1 km 10

 1 ∴ 10 x + 5

 = 36 5 × 60 × 60

 ⇒ 1 = 1 10(x +5) 500

⇒  x + 5 = 50
⇒  x = 45 kmph

1. A train is running at a speed of 90 km/hr. If it crosses a signal in 10 sec., the length of the train (in metres) is
1. 150
2. 324
3. 900
4. 250

1. Speed of train = 90 kmph

 = 90 × 5 metre/second 18

= 25 metre/second
If the length of the train be x then,
 Speed of train = Length of train Time taken in crossing the signal

 ⇒  25 = x 10

⇒  x = 250 metre

##### Correct Option: D

Speed of train = 90 kmph

 = 90 × 5 metre/second 18

= 25 metre/second
If the length of the train be x then,
 Speed of train = Length of train Time taken in crossing the signal

 ⇒  25 = x 10

⇒  x = 250 metre