## Speed, Time and Distance

#### Speed, Time and Distance

1. How long does a train, 75 metre long, moving at 60 km/hr take to pass a certain telegraph post?
1. 3.5 seconds
2. 4.5 seconds
3. 5 seconds
4. 5.4 seconds

1. Distance covered by train = Length of train
Speed of train = 60 kmph

 = 60 × 5 m./sec. 18

 = 50 m./sec. 3

 ∴  Required time = Distance Speed

 = 75 seconds (50/3)

 = 75 × 3 seconds 50

= 4.5 seconds

##### Correct Option: B

Distance covered by train = Length of train
Speed of train = 60 kmph

 = 60 × 5 m./sec. 18

 = 50 m./sec. 3

 ∴  Required time = Distance Speed

 = 75 seconds (50/3)

 = 75 × 3 seconds 50

= 4.5 seconds

1. A train 240 metres in length crosses a telegraph post in 16 seconds. The speed of the train is
1. 50 km/hr
2. 52 km/hr
3. 54 km/hr
4. 56 km/hr

1. When a train crosses a pole it travels a distance equal to its length.

 ∴  Speed of train = 240 = 15 m./sec. 16

 = 15 × 18 kmph. 5

= 54 kmph.

##### Correct Option: C

When a train crosses a pole it travels a distance equal to its length.

 ∴  Speed of train = 240 = 15 m./sec. 16

 = 15 × 18 kmph. 5

= 54 kmph.

1. In what time will a train, 60 metre long, running at the rate of 36 km/hr pass a telegraph post ?
1. 9 seconds
2. 8 seconds
3. 7 seconds
4. 6 seconds

1. Speed of train = 36 kmph

 = 36 × 5 m./sec. 18

= 10 m./sec.
 ∴  Required time = Length of train Speed of train

 = 60 = 6 seconds 10

##### Correct Option: D

Speed of train = 36 kmph

 = 36 × 5 m./sec. 18

= 10 m./sec.
 ∴  Required time = Length of train Speed of train

 = 60 = 6 seconds 10

1. A train 150m long passes a telegraphic post in 12 seconds. Find the speed of the train.(in km/hr)
1. 50
2. 12.5
3. 25
4. 45

1. Distance covered by train in crossing a telegraphic post = length of train

 ∴  Speed of train = Distance Time

 = 150 m./sec. 12

 = 150 × 18 kmph 12 5

= 45 kmph

##### Correct Option: D

Distance covered by train in crossing a telegraphic post = length of train

 ∴  Speed of train = Distance Time

 = 150 m./sec. 12

 = 150 × 18 kmph 12 5

= 45 kmph

1. In what time will a 100 metre long train running with a speed of 50 km/hr cross a pillar ?
1. 7.0 seconds
2. 72 seconds
3. 7.2 seconds
4. 70 seconds

1. Speed of train = 50 kmph

 = 50 × 5 m./sec. 18

 = 125 m./sec. 9

 ∴ Required time = (100/125) seconds 9

 = 100 × 9 seconds 125

= 7.2 seconds

##### Correct Option: C

Speed of train = 50 kmph

 = 50 × 5 m./sec. 18

 = 125 m./sec. 9

 ∴ Required time = (100/125) seconds 9

 = 100 × 9 seconds 125

= 7.2 seconds