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. View Hint View Answer Discuss in Forum

    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. View Hint View Answer Discuss in Forum

    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. View Hint View Answer Discuss in Forum

    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. View Hint View Answer Discuss in Forum

    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. View Hint View Answer Discuss in Forum

    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