Time & Distance (1)

1. A train is running at a speed of 40 km/hr and it crosses a post in 18 seconds. What is the length of the train?
1. 190 metres
2. 160 metres
3. 200 metres
4. 120 meters

Explanation :-

Speed = 40*(5/18) m/sec = 100/9 m/sec
Length of Train(Distance) = Speed * Time
Length of Train(Distance) = (100/9)*18) = 200 metres

2. A train ,130 meters long travels at a speed of 45 km/hr crosses a bridge in 30 seconds. The length of the bridge is
1. 270 m
2. 245 m
3. 235 m
4. 220 m

Explanation :-

Let’s suppose the length of bridge = b metres
Speed = Distance /Time
Speed (in metres) = 45 (5/18) = (25/2) m/s
25/2 = (130 + b)/ 30
375 = 130 + b
b = 245 metres

3. A train has a length of 150 meters . it is passing a man who is moving at 2 km/hr in the same direction of the train, in 3 seconds. Find out the speed of the train.
1. 182 km/hr
2. 180 km/hr
3. 152 km/hr
4. 169 km/hr

Explanation :-

Length of train = 150 metres
Man’s speed = 2 km /h
Relative Speed = total distance / time
Relative Speed = 150/3 = 50 m/s = 50 *(18/5) = 180 km/h
Relative Speed = Speed of train – Speed of man     ( beacause moving in the same direction )
180 = Speed of train – 2
Speed of train = 180 + 2 = 182 km/h

4. A train having a length of 240 m passes a post in 24 seconds. How long will it take to pass a platform having a length of 650 m?
1. 120 sec
2. 99 s
3. 89 s
4. 80 s

Explanation :-

Speed of train = 240/24 = 10 m/s
Total distance = 240 + 650 = 890 m
Speed = distnace /time
10 = 890 /time
Time = 89 sec

5. A train 360 m long runs with a speed of 45 km/hr. What time will it take to pass a platform of 140 m long?
1. 38 sec
2. 35 s
3. 44 sec
4. 40 s