Question

Two trains, A and B, each $50m$ long, are approaching a meeting point travelling with velocities $10m/s$ and $15m/s$ respectively. The tracks of the two trains are perpendicular to each other and both trains are $500$ meters away from the meeting point. How far will be the train A from meeting point when train B crosses the meeting point?

• A. $135m$
• B. $133.3m$
• C. $130.0m$
• D. $123.3m$

Answer 1

The correct option is B $133.3m$

Since train B is traveling with higher speed than train A, B will reach first.
For the last coach of train B to reach meeting point, total distance train B has to travel is $550m$ with velocity $15m/s$.
Time taken to cross $550m$ is
$t=\frac{s}{v}=\frac{550}{15}=36.67s$
In that period train, A moves a distance of
$s=10\times 36.67=366.7m$.
Distance from the meeting point $=500-366.7=133.3m$