## Speed, Time and Distance

#### Speed, Time and Distance

1. A 120 m long train takes 10 seconds to cross a man standing on a platform. What is the speed of the train ?
1. 12 m/sec.
2. 10 m/sec.
3. 15 m/sec.
4. 20 m/sec.

1. In crossing a man standing on platform, train crosses its own length.

 ∴  Speed of train = 120 = 12 m/s 10

##### Correct Option: A

In crossing a man standing on platform, train crosses its own length.

 ∴  Speed of train = 120 = 12 m/s 10

1. A train is 125 m long. If the train takes 30 seconds to cross a tree by the railway line, then the speed of the train is :
1. 14 km/hr
2. 15 km/hr
3. 16 km/hr
4. 12 km/hr

1.  Speed = Distance Time

 = 125 = 4.16m/s 30

 4.16 m/s = 4.16 × 18 5

= 15 km/hr

##### Correct Option: B

 Speed = Distance Time

 = 125 = 4.16m/s 30

 4.16 m/s = 4.16 × 18 5

= 15 km/hr

1. How many seconds will a 500 metre long train take to cross a man walking with a speed of 3
km/hr. in the direction of the moving train if the speed of the train is 63 km/hr ?
1. 25 sec
2. 30 sec
3. 40 sec
4. 45 sec

1. Relative speed of train = 63–3 = 60 kmph

 = 60 × 5 m/sec 18

 ∴  Time = Length of train Relative Speed

 = 500 × 18 = 30 sec. 60 × 5

##### Correct Option: B

Relative speed of train = 63–3 = 60 kmph

 = 60 × 5 m/sec 18

 ∴  Time = Length of train Relative Speed

 = 500 × 18 = 30 sec. 60 × 5

1. A train 100m long is running at the speed of 30 km/hr. The time (in second) in which it will pass a man standing near the railway line is :
1. 10
2. 11
3. 12
4. 15

1. In this situation, the train covers it length.

 Required time = 100 hr. 30 × 1000

 Required time = 100 × 60 × 60 = 12 seconds 30 × 1000

##### Correct Option: C

In this situation, the train covers it length.

 Required time = 100 hr. 30 × 1000

 Required time = 100 × 60 × 60 = 12 seconds 30 × 1000

1. A train 180 m long moving at the speed of 20 m/sec. over-takes a man moving at a speed of 10m/sec in the same direction. The train passes the man in :
1. 6 sec
2. 9 sec
3. 18 sec
4. 27 sec

1. Relative speed of man and train = 20 – 10 = 10m/sec.

 ∴  Required time = 180 = 18 seconds 10

##### Correct Option: C

Relative speed of man and train = 20 – 10 = 10m/sec.

 ∴  Required time = 180 = 18 seconds 10