QJEEM19Ph6bd5: JEE Main 2019 Physics - Class 11 JEEM19Ph6bd5 Solution: A passenger train of length 60 m travels at a speed of 80…

The total distance to be travelled by the train is 60 + 120 = 180 m.

When the trains are moving in the same direction, relative velocity is
v₁ – v₂ = 80 – 30 = 50 km hr^–1

So time taken to cross each other,

t₁ = $$\frac{180}{50\times \frac{{10}^3}{3600}}$$

When the trains are moving in opposite direction, relative velocity is
|v₁ – (–v₂ )| = 80 + 30 = 110 km hr^–1

$$\therefore$$ Time taken to cross each other

t₂ = $$\frac{180}{110\times \frac{{10}^3}{3600}}$$

$$\therefore$$ $$\frac{t_1}{t_2}=\frac{\frac{180}{50\times \frac{{10}^3}{3600}}}{\frac{180}{110\times \frac{{10}^3}{3600}}}$$ = $$\frac{11}{5}$$