Question

a train 150 m long passes a km stone in 15 seconds and another train of the same length travelling in opposite direction in 8 sec. find the speed of the second train.

Answer 1

Given that two trains are of same length i.e..150 mtrs
first train passes the km stone in 15 seconds. here we have time and distance so speed=150/15=10 m/s
we need to find out the second train speed.
suppose the speed of the 2nd train is x m/s
Relative speed of two trains is (10+x)
==> (150+150)/(10+x)=8
==> (300)/(10+x)=8
==> 300=80+8x
==> 300-80=8x
==> 220=8x
:- x=55/2 m/s
convert m/s into km/ph
(55/2)*(18/5)=99kmph
;- The speed of the second train is 99Kmph

Answer 2

Answer:

The speed of second train will be equal to 99 kilometers per hour.

Explanation:

We have given, the same length of two trains = 150m

First train passes the stone in time, t = 15s

Speed of first train $=\frac{150m}{15s}=10m/s$

The length of the stone = 1Km

Consider that 'x' is the speed of second train.

The time taken by the second train = 8sec

Relative speed of two trains will be equal to (10 + x)m/s.

$10+x = \frac{150 + 150}{8}$

$8(10+x)=300$

$8x =300-80$

$8x=220$

$x=\frac{55}{2} m/s$

Here, convert meters into Km and sec into hour.

1m = 10⁻³Km and 1hr = 3600sec

$x=\frac{55}{2}*\frac{3600}{1000}Km/h$

$x=99\;Kmh^{-1}$

Therefore, the speed of second train is equal to 99Km/h.