Question

Two trains A and B of length 400 m each are moving on two parallel tracks with a
uniform speed of 72 km h-in the same direction, with A ahead of B. The driver of
B decides to overtake A and accelerates by 1 ms. If after 50 s, the guard of B just
brushes past the driver of A, what was the original distance between them?
solve using relative velocity concept​

Answer 1

Answer:

450 m

Explanation:

since relative velocity is zero in this case (∵ rel. vel. = 72 + (-72) km/ h)

(d+800) = 0 x 50 + 1/2 x 1 x 2500............(s=ut+1/2 at^2)

therefore, d= 1250 - 800 m

i.e. d = 450 m

here (d+800) is the total distance that has to be covered and 800 means the additional length of train to be covered.