A 120 m long train is moving in a direction with speed 20 m/s. A train B moving with 30 m/s in the opposite direction and 130 m long crosses the first train in a time

Question

A 120 m long train is moving in a direction with speed 20 m/s. A train B moving with 30 m/s in the opposite direction and 130 m long crosses the first train in a time (A) 6 s (B) 36 s (C) 38 s (D) 5 s

Tardigrade Admin · Accepted Answer

Relative velocity of train B w.r.t. to train A is

V_{B A} = (30 m / s) - (- 20 m / s) = 50 m / s

Total distance covered by train B in order to pass the train A is S = length of train A + length of train B

= 120 m + 130 m = 250 m

Hence, time taken by
train B to cross train

A = \frac{S}{V _{A B}}

= \frac{( 250 m )}{( 50 m / s )}

= 5 s

Q. A $120 m$ long train is moving in a direction with speed $20 m / s$ . $A$ train $B$ moving with $30 m / s$ in the opposite direction and $130 m l o n g$ crosses the first train in a time

$6 s$

$36 s$

$38 s$

$5 s$

Q. A 120m long train is moving in a direction with speed 20m/s. A train B moving with 30m/s in the opposite direction and 130mlong crosses the first train in a time

6s

36s

38s

5s

Relative velocity of train B w.r.t. to train A is VBA​=(30m/s)−(−20m/s)=50m/s Total distance covered by train B in order to pass the train A is S = length of train A + length of train B =120m+130m=250m Hence, time taken by train B to cross train A=VAB​S​ =(50m/s)(250m)​ =5s

Q. A $120 m$ long train is moving in a direction with speed $20 m / s$ . $A$ train $B$ moving with $30 m / s$ in the opposite direction and $130 m l o n g$ crosses the first train in a time

$6 s$

$36 s$

$38 s$

$5 s$