Question

The engine driver of a 130 m long Rajdhani Express
lon
travelling at 150 km/h, sees the rear of a 220 m )
goods train, travelling at 80 km/h ahead of him
another track at 8:05:00 a.m. If the Rajdhani Expres
overtakes the goods train at 8:06:30 a.m., how fx
was the goods train when the driver saw its rear a
8:05 a.m.?​

Answer 1

$\huge\fcolorbox {blue}{black}{ANSWER}$

42 m/s, 38 m/s

Let the speeds of the faster train be x m/s and that of the slower train be y m/s.

When the two trains are moving in the same direction:

Relative speed =(x−y) m/s

∴

x−y

130m+110m

=60

⇒ x−y

240

=60

⇒x−y=4 .... (i)

When the two trains are moving in opposite direction:

Relative speed =(x+y) m/s

∴

x+y

130m+110m

=3⇒x+y=80 .... (ii)

Adding eqn (i) and (ii), we get

2x=84

⇒ x=42 m/s

∴ putting value of x in (i), we get

y=38 m/s.