Question

Two trains a and b length of 300m each are moving on two parallel tracks with a uniform speed of 54 kmph in the same direction with the train a ahead of b the driver of train b decides to overtake a and accelerates by 2ms-2. if after 25s, the guard of train b just brushes past the driver of a, what was the original distance between them?

Answer 1

Answer:

Given that,

u

A

=u

B

=72kmh

−1

=72×

18

5

=20ms

−1

Using the relations, s=ut+

2

1

at

2

, we get

S

B

=u

B

t+

2

1

at

2

=20×50+

2

1

×1×(50)

2

S

B

=1000+1250=2250m

Also, let S

A

be the distance covered by the train A, then S

A

=u

A

×t

=20×50=1000m

Original distance between the two trains

= S

B

−S

A

=2250−1000=1250m