Question

A train which is 390 m long, is running at 45 kmph. In what time will it cross a person moving at 9 kmph in same direction ?

a. 26 sec

b. 39 sec

c. 36 sec

d. 29 sec

Answer 1

C) 36 sec
I hope it's help you friend because it's a right answer

Answer 2

Answer:

the train will cross the person in 26 seconds.

First option is correct.

Step-by-step explanation:

The speed of train = 45 kmph

Speed of person = 9 kmph

Both are moving in the same direction. Hence, the relative speed would be the sum of their individual speed.

Relative speed = speed of train + speed of person

v = 45 + 9

v = 54 kmph

We convert this speed in m/s

$v=54\cdot\frac{5}{18}\\\\v=15m/s$

In order to cross the person, the train will cover a distance equal to its length.

Thus, d = 390 m

Therefore, time taken by train to cross the person is given by

$t=\frac{d}{v}\\\\t=\frac{390}{15}\\\\t=26s$

Thus, the train will cross the person in 26 seconds.

First option is correct.