Question

( bullet ) Let ( u & v ) be the velocity of the two trains named ( A & B ).
While overtaking the relative velocity of train A with respect to ( mathrm{B}=mathrm{u}-mathrm{v} ).
While crossing, the relative velocity of train A with respect to ( B=u+v ).
- Total distance to be travelled by Train A while crossing ( =100+100= ) 200
So,
( 20=200 div u-v )
( Rightarrow mathrm{u}-mathrm{v}=10 ldots .1) )
( mathrm{AlsO} )
( 10=200 div u+v )
( Rightarrow mathrm{u}+mathrm{v}=20 ldots ldots .2) )
( bullet ) On solving the equation ( 1 & 2, ) we get; ( bullet * )
( mathrm{u}=15 mathrm{M} / mathrm{S} ) of the train ( mathrm{A} / ) First Train.
( mathrm{v}=5 mathrm{M} / mathrm{S} ) of the train ( mathrm{B} / mathrm{Second} ) Train.

# Two trains each of length 100 m are running on parallel tracks. One overtakes the other in 20 s when they are moving in the same direction and crosses the other in 10 s when they move in the opposite directions. The velocities of the two trains are (1) 15 m/s & 5 m/s (2) 25 m/s & 15 m/s (3) 10 m/s & 10 m/s (4) 30 m/s & 10 m/s

Solution