Question

A 200 m long train moving with velocity 20 m/s overtakes a man running in the same direction in 20 sec . how long the train will take to overtake the man if he was running in opposite direction ? (1) 10/3 sec (2) 20/3 sec (3) 5/3 sec (4) 3 sec

Answer 1

let the speed of the man be x m/s
speed of the train= 200 m/s
Distance = speed x time
200m (length of train)= (20-x) x 20 s
(man's speed to be subtracted as he is also running)
so x= 10 m/s
When train and man are in opposite direction
200 m = (20+10) t
so t=20/3 seconds

Answer 2

Answer:

Option (2) is the required answer. Solution is given below.

Explanation:

Dear Student

Let the speed of the man be x m/s

Speed of the train = 20 m/s

Time = 20 sec

Distance = 200 m

We know,

Distance = Speed x Time

200 m = (20 - x)m/s x 20 s

Note: x is subtracted from the speed of the train because man is also continuously running.

Therefore, x = 10 m/s

When the man is running in opposite direction to the train, then,

200 m = (20 + 10)t

So, t = 20/3 sec

Option (2) is correct.

Regards