Question

Two trains each of length 150 metres are moving in opposite with equal speed of 90 km per hour the time taken by the trains to cross each other will be what .

Answer 1

${\bold{\underline{\underline{Answer:}}}}$

${\bold{\therefore Time\:taken=3\:sec}}$

${\bold{\underline{\underline{Step-by-step\:explanation:}}}}$

• In the given question information given about two trains each of length 150 metres are moving in opposite with equal speed of 90 km per hour .

• We have to find time taken by the trains to cross each other.

$\underline \bold{Given : } \\ \implies Speed \: of \: train \: a = 90 \: km/h \\ \\ \implies Speed \: of \: train \: b= 90 \: km/h \\ \\ \implies Distance =150 \: m \\ \\ \underline \bold{To \: Find:} \\ \implies Time \: taken = ?$

• According to given question :

$\bold{Using \: Relative \: motion : } \\ \implies Let\: speed \: of \: train \: a = 0 \\ \\ \implies Relative\:speed \: of \: train \: b = 90 + 90 = 180 \: km/h \\ \\ \bold{\implies Relative\:speed \: of \: train \: b = 50 \: m/s} \\ \\ \bold{For \: Finding \: time : } \\ \implies Time = \frac{Distance}{Speed} \\ \\ \implies Time = \frac{ \cancel{150}}{ \cancel{50}} \\ \\ \bold{\implies T= 3 \: sec}$

Answer 2

Answer:

• Time taken = 3 sec

Step-by-step explanation:

$\bold{Using \: Relative \: motion : } \\ \implies Let\: speed \: of \: train \: a = 0 \\ \\ \bold{\implies Relative\:speed \: of \: train \: b = 50 \: m/s} \\ \\ \bold{For \: Finding \: time : } \\ \implies Time = \frac{Distance}{Speed} \\ \\ \implies Time = \frac{ \cancel{150}}{ \cancel{50}} \\ \\ \bold{\implies T= 3 \: sec}$